DIVER OSINT CTF 2026 "kaitai1" Writeup

This article was automatically translated from Japanese by AI.

Challenge

DIVER OSINT CTF 2026 “kaitai1”

Solution

The utility pole had graffiti reading “ねこかいたいね,” but I could not find any other clues in the image, so I searched online, mainly on social media, for similar photos. I found a post on X and a post on Instagram, which revealed that the distant rooftop sign beyond the vacant lot read “パチンコ ミナミ” (Pachinko Minami).

Searching for the Pachinko Minami sign led to a post on X showing the sign, identifying it as Pachinko Minami in Shimokitazawa. Its address was near 2-4-7 Kitazawa, Setagaya-ku, Tokyo.

Exploring the area where this sign would be visible on Google Maps led me to a location near 35.6626, 139.6684, in Kitazawa 2-chome, Setagaya-ku.

Searching for 世田谷区 地番 and similar terms turned up a list of PDFs showing land lot numbers. From there, I opened 040.pdf, a map covering Kitazawa 2-chome.

After narrowing down the approximate location, I compared the divisions between buildings and the images to identify the land lot number as 959-23.

Source: Google Map / Tokyo Metropolitan Government Bureau of Taxation cadastral map (040.pdf), September 10, 2026

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Diver26{959-23}