He once met Nobunaga Shimazaki during 81 Produce's 1st audition on 2007, where they were both finalist during that audition. Almost 8 years later, they would star together in Ore Monogatari!!, where Eguchi played Takeo Gouda and Shimazaki played Makoto Sunakawa.
In 2017, Eguchi launched a manga about his life called Eguchi Takuya no Gainen Planet, published on Kadokawa's Dengeki Girl's Style Online website.
During high school, he listened to Masaya Onosaka's radio show which he tuned on during his late night study sessions, and became interested on voice acting.
He is a part of the trio Trignal with fellow seiyuus Ryouhei Kimura and Tsubasa Yonaga and host Radio for Kiramune label, and with fellow seiyuu Yuuki Ono in Team YouTak.