A lil Introspection helps reveal you and what your feeling given time. The "yet" is probably the transition from platonic friend feelings to those of romantic. Its always usually a gradual thing and cant be forced. Just considering the thought isn't enough to solidify feelings. Theres alot to consider (the nature of their relationship changing, his own feelings toward this, whether he can even like a guy, and how it will affect the future.) Tokio has to consider all this, and in the end he himself has decided that kazuho is too important to him to ever lose in any capacity. In the time they've spent together now with a new romantic perspective, he can see for himself what it would be like to love him in that sense. If it was the opposite he'd just tell him, "im sorry but I don't think its can see you that way."
It actually happened with me. I saw someone as good friend for 6.years until they told me they actually had feelings for me the whole time. And i did told them I don't feel the same. But since they put the idea in my head that they had feelings for me. And i did like them as a friend I thought about it often and eventually I did developed feelings for them too. So the next time they confessed again I did not reject them. I think it's the information that helped to figure out I want the relationship I have with them to be the same or if i can handle more. I did end up noticing them a lot more after so I think it's like that
As much as I like reading romance and feel butterflies when characters fell inlove, the lines "I need to understand your feelings, i dont like you yet, i want to think it over, so could you wait for me" are something I don't understand.
Isn't the fact that you are even considering the thought of being together mean you like them? Or is that different. What more are you looking to find out? Would waiting make you consider whether you like them?