--- title: "isshoni. Day Log B6 Slim: 3-Month Undated Planner" canonical: "https://stationerytimes.com/guides/daigo-isshoni-day-log/" description: "DAIGO isshoni. Day Log: an undated B6 Slim planner with 92 day-per-spread pages with a 0:00 to 23:00 timeline, habit tracker, four season covers and prices." category: "Notebooks" type: "Planner" published: 2026-10-28 updated: 2026-10-28 author: "Ellis Penhale" publisher: "Stationery Times" sources: 5 products: - name: "isshoni. Notebook Day Log B6 Slim, green (R1826)" brand: "DAIGO" brand_origin: "Japan" made_in: "Japan" material: "Polypropylene (PP) cover; paper; single-corner elastic band" price_band: "$$ ($5–20 per notebook, typical US retail, October 2026)" manufacturer: "Daigo Corporation (Osaka)" model: "R1826" gtin: "4902041418263" url: "https://www.maruzenjunkudo.co.jp/products/4902041418263" --- # isshoni. Day Log B6 Slim: 3-Month Undated Planner > The isshoni. Day Log from Daigo of Osaka is an undated three-month planner in B6 Slim, 180 × 110 × 10 mm, with 194 pages. It gives each of 92 days a two-page spread with a 0:00 to 23:00 timeline, and adds monthly plans, a habit tracker and a monthly review. Four season-colored covers close with one elastic band. - URL: https://stationerytimes.com/guides/daigo-isshoni-day-log/ - Category: Notebooks - Author: Ellis Penhale - Published: 2026-10-28 - Updated: 2026-10-28 ![Four isshoni. Day Log B6 Slim notebooks in spring green, summer blue, autumn red and winter gray, 110 × 180 mm, and an open day spread](https://stationerytimes.com/images/raster/daigo-isshoni-day-log-illustration-16x9.png?v=37596068) *The four season covers to scale at 1 mm = 1.05 px, and a day spread drawn by eye; tints are representative.* Original illustration made for this guide. © Stationery Times. Original drawing (SVG): . Drawings © 2026 Stationery Times, reusable with credit under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). ## Product facts | Product | Brand | Brand origin | Made in | Material | Released | Price range (typical US retail, October 2026) | |---|---|---|---|---|---|---| | isshoni. Notebook Day Log B6 Slim, green (R1826) | DAIGO (by Daigo Corporation (Osaka)) | Japan | Japan | Polypropylene (PP) cover; paper; single-corner elastic band | – | $$: $5–20 per notebook | - Made in (isshoni. Notebook Day Log B6 Slim, green (R1826)): Japan. Maruzen Junkudo's listing gives Japan as the country of origin, and The Journal Shop and bungu.store say made in Japan; Daigo's own isshoni. page doesn't list the Day Log. Source: https://www.maruzenjunkudo.co.jp/products/4902041418263 ## Key takeaways - Maruzen Junkudo lists the Day Log at 180 × 110 × 10 mm with 194 pages, a PP cover and 185 g; The Journal Shop gives 399 g, which we read as a shipping weight. - It covers about 92 days: each day is a two-page spread with a timeline from 0:00 to 23:00, so the 184 daily pages are most of the book. - Yoseka lists the page split as 6 monthly-planning pages, a 2-page overview of three months plus one ahead, 184 daily pages and a 2-page habit tracker. - Four covers follow the seasons: green for spring, blue for summer, red for autumn and gray for winter, codes R1826 to R1829. - Japan's list price is ¥1,540 (about US$9.70) with tax, and the US-facing shops we checked listed it within our $$ band ($5–20) on October 28, 2026. ## What is the isshoni. Day Log? **It is an undated three-month planner and diary from Daigo of Osaka, in a slim B6 size.** The Journal Shop calls it a manageable alternative to a full-year diary: you start when you are ready, not when the calendar says so. It belongs to Daigo's isshoni. line for office workers, which our [DAIGO story](https://stationerytimes.com/stories/daigo-history/) covers. Each day gets a two-page spread, so the Day Log suits people who want to log what happened as well as plan it. ## What are its specs? **180 × 110 × 10 mm, 194 pages and a PP cover, per Maruzen Junkudo.** Daigo's own isshoni. page doesn't list the Day Log, but its June 2026 release gives the same size and page count. | Spec | Value | |---|---| | Size | 180 × 110 × 10 mm (7.1 × 4.3 × 0.4 in), B6 Slim | | Pages | 194 | | Weight | 185 g (6.5 oz) per Maruzen; 399 g per The Journal Shop | | Cover | Polypropylene (PP), with a single elastic band at the lower right | | Layout | Grid, per Maruzen's title; the grid spacing isn't stated | | Dates | None (undated) | | Colors | Green R1826, blue R1827, red R1828, gray R1829 | | JAN (green) | 4902041418263 | The two weights disagree. 399 g is probably a shipping weight with packaging, but the shops don't say. ## How are its 194 pages laid out? **Mostly day spreads: 184 of the 194 pages are the 92 days.** Yoseka lists the split as 6 pages of monthly planning, a 2-page overview, 184 pages of daily planning and a 2-page habit tracker. ![The 194 Day Log pages: 8 front pages, 184 pages of 92 daily spreads and 2 back pages](https://stationerytimes.com/images/daigo-isshoni-day-log-pages.svg?v=455c4c4f) *The 194 pages at 4.2 px per page, in the split Yoseka lists. Original illustration made for this guide. © Stationery Times.* Daigo's text, as Maruzen gives it, calls each day a "Today's Plan" spread with a timeline from 0:00 to 23:00 for appointments, logs and to-dos. The overview spread shows about three months plus one month ahead, for long projects and plans that cross months. At the back, a habit tracker records goals and a monthly review page records good points and regrets, so you can see progress after three months. ## What do the four covers mean? **They are the four seasons, so each three-month book can have its own color.** Green is spring's fresh leaves, blue is summer's sea, red is autumn leaves and gray is a snowy winter day, per Maruzen and Yoseka. Maruzen says the idea is to enjoy a different color every three months. Four books make a year. ## Who is the Day Log for? **In our view, for people who like to see a day's hours at a glance.** The 0:00 to 23:00 timeline helps if your day is cut into meetings, and the habit tracker suits one goal at a time. If you want a whole year in one book, see our [planners roundup](https://stationerytimes.com/guides/best-productivity-planners/). To choose between formats, our guide to [how to choose a planner](https://stationerytimes.com/guides/how-to-choose-a-planner/) explains weekly against daily layouts. ## How many Day Logs make a year? **Four, if you fill every day: 4 × 92 = 368 days, a little over a year, by our arithmetic.** The season colors nudge you to buy one per quarter. Because the book is undated, skipping days stretches each one. ## Are there special designs? **Yes: Daigo's June 15, 2026 release lists a Day Log with Furukawa Shiko artwork, in a seal, a dog, a panda and a cat.** It keeps the B6 Slim size and 194 pages, adds stickers for decorating a planner, and lists at ¥1,925 (about US$12) with tax. ## How much does it cost and where can you buy it? **Yoseka listed it at US$18.00 and The Journal Shop at £14.99 (about US$20) on October 28, 2026, in our $$ band ($5–20).** Yoseka is in New York; The Journal Shop prices in pounds. bungu.store, a Japan-based shop, listed it at ¥3,100 (about US$20). Maruzen Junkudo listed ¥1,540 (about US$9.70) with tax, so US-facing prices are roughly double. The Furukawa Shiko version, with stickers, lists at ¥1,925 (about US$12) with tax. We found no listing at JetPens or Jenni Bick on that date. Daigo also sells covers with a built-in pen case; our [isshoni. PVC pen case notebook cover](https://stationerytimes.com/guides/daigo-isshoni-pen-case-notebook-cover/) guide gives their closed sizes, so you can check whether a Day Log's 180 × 110 mm body suits one. ## Frequently asked questions ### Is the isshoni. Day Log dated? No. Yoseka and The Journal Shop both call it undated or date-free, so you start on any day and write the dates in yourself. ### How long does one Day Log last? About three months of daily use: it has 92 day spreads. If you skip days, a notebook lasts longer, since the days aren't tied to a calendar. ### How many pages does the Day Log have? 194, which Maruzen Junkudo, The Journal Shop, Yoseka and bungu.store all list. Of those, 184 are the 92 two-page daily spreads. ### Does it have a habit tracker? Yes. A two-page habit tracker at the back lets you record goals and check them off each day, and a monthly review page lets you note what went well, per Maruzen's description of Daigo's text. ### Is it a planner or a diary? Both: Yoseka calls it a diary and The Journal Shop a planner. You write appointments and to-dos on the timeline and daily logs beside it, and with no printed dates it works as a diary you fill in as you go. ### Does the Day Log have a pen loop? None of the listings we read mention one. They describe a single elastic band anchored at one corner, which keeps the cover closed in a bag. ### Does Daigo make a Day Log with sticker extras? Yes. Daigo's June 15, 2026 release lists a Day Log in four Furukawa Shiko animal designs with bonus stickers for decorating, at ¥1,925 (about US$12) with tax. ## Sources - [Maruzen Junkudo (Japanese): isshoni. Notebook Day Log B6 Slim green R1826 (180×110×10 mm, 185 g, 194 pages, PP cover, layout text; ¥1,540 with tax; JAN 4902041418263; read October 28, 2026)](https://www.maruzenjunkudo.co.jp/products/4902041418263) - [Yoseka Stationery: DAIGO isshoni. Notebook - Day Log - B6 Slim (US listing: 194 pages, page split, four colors, 7.1 × 4.3 in; read October 28, 2026)](https://yosekastationery.com/products/isshoni-notebook-day-log-b6) - [The Journal Shop: Isshoni Day Log B6 Slim Notebook (180×110×10 mm, 194 pages, 399 g, materials, made in Japan; priced in pounds)](https://www.thejournalshop.com/products/daigo-isshoni-day-log-b6-slim-notebook) - [bungu.store: isshoni. 3-Month Day Log Notebook (92 days, layout, four seasonal colors; yen prices)](https://bungu.store/products/isshoni-3-month-day-log-notebook-daigo) - [Daigo (Japanese): press release, isshoni. x Furukawa Shiko second collaboration (Day Log B6 Slim 180 × 110 mm, 194 pages, ¥1,750 before tax, June 15, 2026)](https://www.daigo.co.jp/press-release/10420/)