Blue Archive has officially revealed Kasumi in her swimsuit outfit through a new Student Introduction published on September 6, 2026. The visual retains the Hot Spring Development Department president's familiar white lab coat and eyewear while pairing them with the swimsuit design previously seen during the 2025 summer event.
The reveal comes just ahead of the return of Natsuzora no Yakusoku, which will rerun beginning September 9, 2026 after maintenance. The original event ran from July into August 2025 and brought together the Tea Party, Justice Realization Committee and the disruptive activities of Gehenna's Hot Spring Development Department.
Quick Summary
- Game: Blue Archive
- Japanese title: ブルーアーカイブ
- Character: Kinugawa Kasumi
- Japanese name: 鬼怒川カスミ
- New version: Kasumi (Swimsuit)
- Announcement type: official Student Introduction
- Announcement date: September 6, 2026
- Announcing account: Blue Archive Official Japan
- Official X: @Blue_ArchiveJP
- School: Gehenna Academy
- Year: second year
- Club: Hot Spring Development Department
- Position: department head
- Character voice: Sumire Uesaka
- Kasumi profile age: 16
- Birthday: May 24
- Height: 148 cm
- Hobbies: explosions and hot spring development
- Swimsuit visual: black swimsuit
- Outerwear: Kasumi's signature white lab coat
- Accessory: sunglasses / goggles
- Related event: 夏空のやくそく
- Event status: rerun
- Rerun date: September 9, 2026
- Start time: after maintenance
- Original event period: July 22–August 6, 2025
- Original context: 4.5th Anniversary summer event
- Swimsuit Kasumi in 2025: appeared in the event story
- Current status: received an official Student Introduction
- Swimsuit-version rarity: not announced in the verified official material
- Combat role: unannounced
- Skill set: unannounced
- Attack / defense type: unannounced
- Pickup title and period: not yet detailed
- Limited / permanent status: not confirmed in the verified announcement
- Game platforms: iOS and Android
- Developer: NEXON Games
- Japanese operator: Yostar
- Official event PV: available
- Original event PV date: July 20, 2025
- Event PV runtime: approximately 1 minute 16 seconds
Swimsuit Kasumi and Natsuzora no Yakusoku
Swimsuit Kasumi Finally Receives an Official Student Introduction
The latest post introduces Kasumi as the head of the Hot Spring Development Department after changing into a swimsuit.
Blue Archive makes it clear that neither summer nor a resort setting does anything to suppress her usual personality. Her obsession with “development” remains intact, with the official caption once again leaning into Kasumi's explosive outlook and her declaration that the world will end with a bang.
The Student Introduction format is particularly notable because the swimsuit itself is not a completely new design created in 2026.
Swimsuit Kasumi had already appeared in the story of Natsuzora no Yakusoku in 2025, where she and the Hot Spring Development Department became part of the chaos surrounding the Trinity characters' attempted vacation.
Natsuzora no Yakusoku Returns on September 9
Blue Archive previously confirmed that the limited-time event “夏空のやくそく” will return on September 9, 2026 after maintenance.
The original event ran from July 22 through August 6, 2025 and served as one of the major pieces of content surrounding the Japanese version's 4.5th Anniversary.
Its story begins with the Tea Party visiting a private beach for a vacation. Mika sets out to make sure Nagisa can actually relax, only for one problem after another to interfere.
The Hot Spring Development Department becomes one of those sources of trouble, directly tying Kasumi's swimsuit appearance to the event now returning in 2026.
The White Lab Coat Survives the Trip to the Resort
The newly released visual keeps several design elements immediately associated with Kasumi.
She wears a black swimsuit while retaining the white lab coat associated with the Hot Spring Development Department. Sunglasses sit above her face, and her hairstyle has been adapted for the summer setting.
Keeping the lab coat also matches how Swimsuit Kasumi was presented during the 2025 event. Being at a resort clearly does not make her abandon her role as the leader of a group that treats practically any promising location as a potential hot spring development site.
The official introduction even says that Kasumi's development-first mindset appears to remain perfectly normal wherever she goes.
Swimsuit Kasumi's Gameplay Details Remain Unannounced
What cannot yet be assumed is Swimsuit Kasumi's gameplay kit.
The verified Student Introduction does not provide her rarity, Striker or Special position, attack type, defense type, EX Skill, Normal Skill, Passive Skill, Sub Skill, or terrain affinities.
Full recruitment details are also absent from the material verified for this article. It would therefore be premature to label the swimsuit version limited or permanent based on banner patterns or community expectations.
Kasumi's original version has been playable since 2023 as a ★3 student, but the original unit's statistics and kit should not be carried over to a separate swimsuit variant.
Further gameplay information will need to come from a Student Skill Introduction, recruitment announcement or another official Blue Archive update.
The 2025 Event Was Swimsuit Kasumi's First Stage
Natsuzora no Yakusoku originally launched during the summer of 2025 with several Trinity students at the center of its campaign.
During the original run, Seia (Swimsuit) and Hasumi (Swimsuit) appeared in the initial pickup, while Ichika (Swimsuit) was available through event rewards. Mika and Nagisa also received swimsuit versions during the wider 4.5th Anniversary campaign.
Kasumi and Meg from Gehenna appeared in the story wearing swimsuits, but their roles at the time were on the story side rather than among the newly introduced swimsuit student lineup for that period.
The official event PV runs for roughly 1 minute and 16 seconds and presents the Tea Party's vacation as it is repeatedly disrupted by trouble. That makes its footage the most relevant visual context for the current article, as the new Kasumi reveal directly accompanies the event's rerun.
Why This Matters
1) A story-only swimsuit design is now receiving its own Student Introduction
Swimsuit Kasumi was already familiar from the 2025 event, but the 2026 announcement gives the outfit a dedicated official spotlight.
2) The reveal arrives immediately before the event rerun
Only a few days separate the September 6 Student Introduction from the September 9 rerun, reinforcing the version's connection to Natsuzora no Yakusoku.
3) Kasumi's characterization remains intact
Even in swimwear, she keeps her white lab coat and is still portrayed as being obsessed with hot spring development and explosions.
4) The most important gameplay information is still ahead
Rarity, role, skills and recruitment details have yet to be disclosed, leaving major implementation details for a later official update.
Game and Event Information
For now, the additional important information currently known includes:
- Kasumi's full name is Kinugawa Kasumi
- her Japanese name is 鬼怒川カスミ
- she is a Gehenna Academy student
- Kasumi is a second-year student
- she heads the Hot Spring Development Department
- Kasumi is voiced by Sumire Uesaka
- her original profile lists her as 16 years old
- her birthday is May 24
- she is 148 cm tall
- her hobbies are explosions and hot spring development
- Kasumi believes locations with hot spring potential should be developed
- her swimsuit version retains the white lab coat as a defining visual element
- the newest Student Introduction was published on September 6, 2026
- the official post says her development-first philosophy remains unchanged at a resort
- Natsuzora no Yakusoku will rerun beginning September 9, 2026
- the rerun starts after maintenance
- the rerun end date was not included in the initial verified announcement
- the original event began on July 22, 2025
- the original event ended on August 6, 2025 at 10:59 AM JST
- the original story takes the Tea Party to a private beach
- Mika attempts to ensure Nagisa can enjoy her vacation
- a series of problems disrupts that plan
- the Hot Spring Development Department appears in the story
- Swimsuit Kasumi already had a character appearance in the original event
- Meg also appears as part of the Hot Spring Development Department
- Swimsuit Ichika was one of the original event rewards
- the original event included a deck-building roguelike mini-game
- the official Natsuzora no Yakusoku event PV was released in July 2025
- the event PV runs for approximately 1 minute 16 seconds
- Swimsuit Kasumi's rarity had not been announced through the Student Introduction when this article was verified
- her combat position remains unannounced
- her attack and defense types remain unannounced
- her EX Skill and other skills remain unannounced
- limited or permanent status has not been confirmed
- full recruitment details are awaiting another official announcement
- the original Kasumi unit's kit is not being used to assume the swimsuit version's abilities
- Blue Archive is developed by NEXON Games
- the Japanese version is operated by Yostar
- the game is available on mobile devices
- official game information is available through the Blue Archive Official Website
- official updates are available through Blue Archive Official X
- the latest Student Introduction is available through the Swimsuit Kasumi Official X Post
- the rerun announcement is available through the Natsuzora no Yakusoku Rerun Official X Post
- the event video is available through the Natsuzora no Yakusoku Official Event PV
- the Android version is available through Blue Archive on Google Play
Closing
Swimsuit Kasumi now has an official Student Introduction after the design first appeared during Natsuzora no Yakusoku in 2025. The reveal comes directly ahead of the event's return on September 9, 2026.
The character reveal has not yet been accompanied by a complete combat kit or recruitment breakdown. Rarity, role, skills and limited-versus-permanent status remain details to watch for in Blue Archive's next official announcements.
- Blue Archive Official X — Official Kasumi Swimsuit Student Introduction
- Blue Archive Official X — Official Natsuzora no Yakusoku Rerun Announcement and September 9 Start
- Blue Archive / YouTube — Official Natsuzora no Yakusoku Event Promotional Video
- Google Play — Official Japanese Blue Archive Store Page
- 4Gamer — Original 2025 Natsuzora no Yakusoku Event and 4.5th Anniversary Details
- Gamer — Original Kasumi Profile, Voice Actor, and 2023 Playable Debut Details
- gamebiz — Original Natsuzora no Yakusoku Event Period, Story, Rewards, and Mini-Game Details
