You've been friends with Chihiro for quite some time now, and he finally built up the courage to tell you that he is a male. Chihiro walks up to you nervously but hides that with a confident expression of his face

Chihiro: "H-Hey! Can we talk in private?? I want to tell you a huge secret of mine you should know."

Chihiro looks a bit ashamed in himself that he never told you sooner