Gekko Kugimiya (born 1953) was a homeless Japanese man who lived in Kabukicho, Tokyo during the 1980s. On 12 December 1988, his friend Takeji Kitabayashi told him that their friend Saku had just gotten back from a job for Tachibana Real Estate and had moved on to Public Park 3, and Kazuma Kiryu overheard the conversation and used it to continue his investigation into Tetsu Tachibana.