What is ジェットストリーム 黒インク?
If you've ever browsed a Japanese stationery aisle, you already know the name: Jetstream. Mitsubishi Pencil's iconic oil-based ballpoint has a cult following for its ultra-low-friction ink — and Daiso quietly stocks it for just ¥110 (about $0.70 USD). That "¥110 for THIS?!" moment is very real.
This version packs a 0.5mm ball tip loaded with Jetstream's signature super-low-friction ink, delivering a noticeably smoother glide than any generic ballpoint. The specs back it up: compared to conventional oil-based pens, Jetstream reduces writing friction by roughly 30% at 150g pressure and 40% at 100g pressure. In plain terms — it writes like butter, whether you're pressing hard or barely touching the page. Ink is black, dense, and dries fast, so smearing is rarely an issue.
The body measures approximately 1cm × 14cm × 1.5cm — slim and pocket-friendly. Materials include recycled PC resin and recycled PBT resin for the barrel, an ABS resin tip section, and a rubber grip for comfort during long writing sessions. Two engineering details worth noting: a twin-ball mechanism prevents ink backflow, and a built-in spring-tip** guards against unwanted ink flooding. These aren't gimmicks — they're the same core tech found in full-price Jetstream pens at ¥220–¥330 in convenience stores. Proudly made in Japan.
Available tip sizes across the Daiso Jetstream lineup typically include 0.38mm, 0.5mm, and 0.7mm — though stock varies by location. This listing covers the standard 0.5mm black ink variant, widely considered the sweet spot between precision and visibility.
Source: daisonet.com
How to Use It — Hack Ideas
Primary Use: Everyday writing — note-taking, form-filling, journaling, office paperwork. The fast-drying black ink makes it ideal for left-handed writers who typically battle smear marks with ballpoints.
Hack #1 — The "Planner Line Art" Pen: The 0.5mm tip and consistent ink flow make this a surprisingly capable tool for hand-drawn planner layouts and bullet journal headers. Skip the expensive fineliner for ruled lines and boxes — the Jetstream lays down clean, uniform strokes that hold up beautifully under highlighter passes without bleeding or feathering.
Hack #2 — The Backup Stylus Carrier: Stash one Jetstream in every bag, jacket pocket, and desk drawer you own. At ¥110, buying four or five to scatter across your daily life costs less than a single convenience-store pen purchase. Treat it as your "always-there" pen ecosystem — never scramble for a working pen again. Some users even tape one to the inside of a clipboard or notebook cover for instant access.
Bonus Tip: If your Daiso location carries replacement refills, the 0.5mm size is the easiest to source. Buy the refill when you see it — refill availability varies significantly by store and restock cycle.
Reviews & Verdict
Community sentiment across Japanese and Korean Daiso shoppers lands in the same place: genuine disbelief at the price point. Reviewers consistently note that the writing feel is indistinguishable from full-priced Jetstream pens sold at stationery shops and convenience stores. The phrase "クセになるなめらかな書き味" (addictively smooth writing feel) printed on the packaging isn't marketing fluff — users confirm it repeatedly.
A few practical caveats worth knowing: stock levels are unpredictable. Some stores receive consistent supply across 0.38/0.5/0.7mm variants; others may only carry one tip size at a time. The dual-color (2-color) versions show up inconsistently and tend to sell out fast — regulars advise grabbing them immediately when spotted. The ¥300 Jetstream multi-function variants, also occasionally found at Daiso, offer sturdier barrels for daily carry but are a separate product tier.
The main caveat: replacement refill availability is hit-or-miss. If long-term use matters to you, prioritize the 0.5mm size since it's the easiest to cross-source at stationery shops if Daiso runs out. Overall, this is one of those rare finds where a brand-name product's quality survives the ¥110 price tag completely intact. For students stocking up for exams, office workers who burn through pens, or anyone who just wants a reliable daily writer — this is a no-brainer pickup.
Value Score: 92/100
Full Jetstream engineering — friction-reducing ink, twin-ball anti-backflow, spring-tip protection, Made in Japan — at roughly one-third the convenience store price. The minor stock unpredictability is the only thing keeping this from a perfect score. A true Daiso gem — don't miss this one.
