When the show started, Takeuchi was an inexperienced actor and the director criticized his performance, telling him that he had "eyes of a dead fish" or how his acting is boring, and even compared him to other Kamen Rider actors. He took the director's words seriously and continued the role till the series ended.
He later met the director and this time, Ishida told Takeuchi that he has become a good actor and stated that he wants to work with him again in the future. The actor recalled, "If you're going to be a Kamen Rider, you'll encounter Ishida, who is tough with his words." Takeuchi feels grateful for the role as the franchise was a starting point in many actors' lives and he challenged himself to take on roles he would never imagined himself in the future.
[Source: Sirabee via Daisuki Toku, IMDb (for Ishida's director credits)]