Takezō Koike is a stage name used by the Japanese voice actor Hideki Ogihara, who was born in Tokyo on November 29, 1972. He is also known by another alias, Kagerou Kirishima. His career has spanned both mainstream anime and adult-oriented games and animations, with the Koike pseudonym primarily associated with roles in adult content.

In anime and original video animation (OVA) aimed at adult audiences, Koike has delivered several notable performances. He played the role of Takurou Hayami in the 2003 OVA series Discipline. He also voiced the character Natsuki in the 2000 series Magical Kanan and reprised the role for the Magical Kanan Summer Special. His other OVA credits include roles in works such as 300 Yen no Otsukiai Anime Edition and Wife Becoming a Meat Toilet for Club Friends While on a Hot Spring Trip... ANIME EDITION.

A significant portion of Koike's work, under this alias, is in adult computer games. He has been active in this field since at least 2000, taking on numerous leading and supporting roles. He is known for his performances in several major game franchises, including portraying Takeshi Yagi in IZUMO2 and its sequel IZUMO2 Gakuen Kyousoukyoku, Ryouta Aizawa in Soul Link, and Kazuma Morisato in the We Without Wings series. He also voiced Kyōichi Hanayama in Cross Days and Midori Bashira in the SHUFFLE! series. In 2022, his credits included a role in the game Chimadori no Ori.

Beyond games and animation, Koike has also contributed to drama CDs and audio dramas, with credits including works like Attribute and Koneko no Iru Seikatsu. His career has involved recurring collaborations with specific game studios, such as Studio e.go! and Navel, for whom he voiced characters in multiple titles. He has also appeared alongside a consistent group of fellow voice actors in the adult game industry. Additionally, he has experience as a radio personality, having hosted programs related to adult game studios.