Hideaki Kobayashi (小林 秀章, Kobayashi Hideaki) is a Japanese cosplayer, computer engineer, music producer, and photographer. He is known for cosplaying as a schoolgirl. He is nicknamed as Sailor Suit Uncle (セーラー服おじさん, Sērā-fuku Ojisan).
Source: “Hideaki Kobayashi (cosplayer)”, English Wikipedia (CC BY-SA 4.0), excerpt