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Have you ever looked up how long you are supposed to keep the Maternal and Child Health Handbook — the boshi techo, Japan's government-issued record of a child's health from birth through early childhood?
Most municipal guidance says roughly this: keep it until the child reaches adulthood, around age 18. After that, almost nothing is written. What happens to it then is left, wordlessly, to the family.
Once a child turns 20, whose is the handbook? Is it acceptable to discard it? Should it be handed over to the child? Should it be kept as part of the family's history?
These questions extend well beyond the boshi techo. The smartphone photos, the parenting logs, the daycare communication notebooks, the records from health checkups — all of this documentation, painstakingly compiled over years of early childhood, still has no designated final destination. This article tries to think through that open question a little early, before it becomes urgent.
What the Maternal and Child Health Handbook was designed to do
The boshi techo (Maternal and Child Health Handbook) is a government-issued document binding a child's and mother's health records into a single booklet. Japan was the first country in the world to introduce a national version, in 1948; it evolved from two earlier instruments — the Pregnant and Postpartum Women's Handbook (1942) and the Infant Physical Development Handbook — which were merged when the Child Welfare Act took effect [1]. The 1965 Maternal and Child Health Act formalized the current name and structure, and municipalities today issue the handbook under Article 16 of that law [1].
In other words, the boshi techo was designed as a public health tool to protect mothers and infants from postwar malnutrition and infectious disease. What to do with it after adulthood was simply out of scope. The absence of a nationally codified retention period reflects that origin. The customary "keep until adulthood" found in most municipal guidance is not a statutory requirement — and what follows is left to each household [note: a citable, specific municipal source for these retention guidelines remains outstanding; see translator notes].
Three destinations for childhood records
When thinking about what a parenting record is for, it helps to distinguish three possible audiences.
1. The parent's own memory
Meal notes, sleep times, mood observations, fleeting words. Most of what gets recorded day to day is written by a parent, for that parent — to preserve what they don't want to forget, to make sense of what they're witnessing. The child, and anyone else, is not the intended reader.
The classic framework here is Robert Butler's 1963 concept of the life review: a psychotherapeutic process of consciously revisiting past experiences to integrate unresolved conflicts and derive meaning, associated with healthy aging: the process, observed in older adults, of consciously revisiting past experience to integrate unresolved tensions and find meaning in one's own history [2]. Butler linked this to depression, personality maturation, and end-of-life meaning-making. Reading back through years of parenting logs functions similarly — a retrospective of an intense chapter of one's own life.
2. The adult child, someday
Records written with the intention of eventually being handed over — "this is who you were in your first years" — have the person at 20 or 30 as their reader. Albums compiled for this purpose, photographs chosen for it, notes written in the voice of a letter: these belong in this category.
The relevant research here comes from McAdams and McLean's work on narrative identity: adult identity is formed through an internalized life story integrating reconstructed past, present, and imagined future [3]. The raw material for that narrative is deeply rooted in conversations, photographs, and records exchanged with caregivers in early childhood — making a handed-over parenting log something close to primary source material for the child's own story [3].
3. Family history, for future generations
Records kept with the expectation of spanning generations — grandchildren and beyond — have future family members as their readers. No single individual is the destination. The record is a contribution to a longer continuity.
The concept of postmemory: the cultural concept that later generations inherit the traumatic or formative experiences of predecessors through objects, photos, and stories, not direct experience, developed by Marianne Hirsch, describes how later generations inherit the experiences of those who came before — through objects, photographs, and stories that act as material anchors for memory that was not directly lived [4]. Family photographs and records function as exactly this kind of physical carrier for postmemory.
These three destinations often overlap. A single notebook can hold a parent's private complaints alongside an entry addressed to the child. The overlap is not a problem. Being aware of which audience you are mainly writing for changes how you write — quietly, without requiring any formal decision.
The destination changes the tone
This is the central point this article wants to make.
When you write with the explicit intention of eventually handing the record to the child it describes, your voice shifts.
- Diagnoses and medical notes become more neutral in their phrasing
- Day-to-day complaints, frustrations with your co-parent, momentary exasperation with the child — these tend to drop out naturally
- "This child is so demanding" becomes "this particular period required a lot of physical energy"
This is self-editing, yes. But it is also the ordinary adjustment that happens in any writing with a specific reader in mind. It is not dishonesty; it is audience awareness.
The inverse is also true. Writing for yourself alone, without the filter of an imagined future reader, allows for more honesty. "Today I genuinely hit my limit." "I cried after dropping them off at daycare." Full honesty is available when the audience is narrow — and records that are legible to anyone often end up saying nothing in particular to anyone.
Neither mode is superior. The point is not to separate the three audiences from the start — just to occasionally ask: who is this entry for? That question, asked periodically, saves confusion later.
"Keeping" and "handing over" are two separate decisions
The question of whether to hand records to an adult child is often implicitly framed as the parent's decision to make. But whether to receive them is also the child's choice.
Some adult children will want to read. Others won't. At 20, a person may have no interest; at 30, having become a parent themselves, they may want to read everything. Depending on the family's circumstances — divorce, estrangement, the emotional weight of a difficult period of childhood — a record can feel like a burden rather than a gift.
What this suggests is a two-stage framing:
- Whether to preserve the record is a decision the parent can make in advance
- Whether to hand it over, and when, is a decision to be made in conversation with the adult the child has become
Deciding in advance that records will automatically be transferred at age 18 or 20 forecloses something. Holding space for "we'll talk about whether you want to see this when you're older" is not evasion — it is a form of respect for the other person's agency.
The separate problem of digital longevity
The discussion so far has been about intent. But digital records carry a separate, structural challenge that has nothing to do with intent.
Will the app you are using today still exist in 20 years? Will the cloud service? Will the file format be readable?
These are not rhetorical questions. HCI researchers have grappled with them for over 15 years. Massimi and Charise introduced thanatosensitivity — designing technology with awareness that users die and digital possessions outlast them — at CHI in 2009 [5]. Brubaker and Callison-Burch's research on Facebook's Legacy Contact feature formalized the problem of post-mortem stewardship: who manages a digital account after the primary user is gone [6].
From the family side, Odom and colleagues' "Technology Heirlooms" research is the most relevant study. Fieldwork with eight families concluded that digital inheritances need physical tangibility, ease of access, and the ability to selectively conceal in order to function as meaningful heirlooms [7]. Services end; formats become obsolete. Think about how many people can play, right now, a video taken on a feature phone ten years ago.
Two practical directions follow.
Check that your records can be exported
Periodically verify whether the app or service you use allows you to export in standard formats — JPEG, MP4, PDF, CSV, Markdown, or similar. If you can export, a service going offline doesn't mean your data is lost; you can move it. When choosing a parenting-log app like Memori, "can I take my data with me?" is a question that matters more than any individual feature [7].
Commit the core to paper
For the records you most want to survive 20 years, printing is an option. You don't need a commercial service — a home printer and a binding strip can produce something durable. Petrelli and Whittaker's family memento research found that physical keepsakes are assigned high subjective value by their owners and tend to persist in households over long periods, in ways that digital files alone do not [8].
"Everything on paper" is unrealistic. "The core — a few dozen prints and a page or two of text — on paper" is achievable and meaningfully more durable.
A few things to do now
The final destination of a childhood record is a long way off. Three modest actions bridge the distance.
- Occasionally sort entries mentally by audience: this one is for me; this one is for them someday
- Verify once that the app you use has a working export function [7]
- Once a year, commit the core of that year — a handful of photographs and a paragraph of text — to something physical [8]
These are less about logistics than about small rituals through which a parent clarifies, for themselves, what the record means.
Summary
A childhood record has no fixed final destination when it is being made. It can belong to the parent [2], to the adult the child becomes [3], or to the family as a continuum [4]. Those destinations can be sorted gradually, through living and writing.
Leaving the destination open is also acceptable. "I'll decide what to preserve; I'll talk with you, when you're grown, about whether you want it" is not irresponsible — it is closer to respecting the other person's future agency.
When the boshi techo was designed in 1948, its designers were focused on protecting mothers and infants from postwar disease [1]. They could not have imagined how that handbook would be read 80 years later. The records being made today are probably similar. The way they will be read in 20 years is not yet visible.
Today's three-line note may arrive, 20 years from now, somewhere that cannot yet be imagined. Writing anyway is enough.
References
- Ministry of Health, Labour and Welfare, Japan. History of major revisions to the Maternal and Child Health Handbook (from the Pregnant and Postpartum Women's Handbook to the Maternal and Child Health Handbook). Maternal and Child Health Division materials. https://www.mhlw.go.jp/stf/shingi/2r9852000001oujo-att/2r9852000001ounf.pdf
- Butler RN. The Life Review: An Interpretation of Reminiscence in the Aged. Psychiatry. 1963;26(1):65–76. doi:10.1080/00332747.1963.11023339. PMID: 14017386.
- McAdams DP, McLean KC. Narrative Identity. Curr Dir Psychol Sci. 2013;22(3):233–238. doi:10.1177/0963721413475622.
- Hirsch M. The Generation of Postmemory. Poetics Today. 2008;29(1):103–128. doi:10.1215/03335372-2007-019.
- Massimi M, Charise A. Dying, death, and mortality: towards thanatosensitivity in HCI. CHI '09 Extended Abstracts. 2009:2459–2468. doi:10.1145/1520340.1520349.
- Brubaker JR, Callison-Burch V. Legacy Contact: Designing and Implementing Post-mortem Stewardship at Facebook. Proc CHI. 2016:2908–2919. doi:10.1145/2858036.2858254.
- Odom W, Banks R, Kirk D, Harper R, Lindley S, Sellen A. Technology heirlooms? Considerations for passing down and inheriting digital materials. Proc CHI. 2012:337–346. doi:10.1145/2207676.2207723.
- Petrelli D, Whittaker S. Family memories in the home: contrasting physical and digital mementos. Pers Ubiquit Comput. 2010;14(2):153–169. doi:10.1007/s00779-009-0279-7.