[Investigating][Severity: Critical][Intrusion]

Daiki Suisan: unauthorized access to its app

On 15 September, Daiki Suisan (Sakai), which runs conveyor belt sushi restaurants and fish shops, found unauthorized access to the system behind its official app. Names, phone numbers, emails, genders, postal codes, addresses and birth dates of 174,933 people who registered between 1 November 2024 and 15 September 2026, including those who left, may have leaked (addresses and birth dates were optional). Passwords are kept on a separate server and were not included.

Disclosed

2026-10-05

Organizations involved

Leaked or at risk

174.9K

174,933

Downtime

Unknown

Timeline

Detected 2026-09-15
Disclosed 2026-10-05
20 days

Attack or cause

Method: [Intrusion]
Impact: [Data leak]
Entry point: Unknown

Data exposed or at risk

[Name][Phone number][E-mail address][Gender][Postal address][Date of birth]

Services hit

[Breached][Critical]
Daiki Suisan official app

Service	Role	Impact level	Note
Daiki Suisan official app	[Breached]	[Critical]

Organizations involved

[Breached][Critical]Osaka, SakaiAccommodation, food and drink174,933 leaked
Daiki Suisan Inc.

						Note
Daiki Suisan Inc.	[Breached]	[Critical]	Osaka, Sakai	Accommodation, food and drink	174,933

Open in organization search

Sources

[1][Official]不正アクセスによる個人情報漏えいのおそれに関するお詫びとお知らせDaiki Suisan · 2026-10-05
[2][News]大起水産に不正アクセス 17万人の情報漏洩かNikkei · 2026-10-05