Muichiro accepted your confession because he's interested in you, Yet he can't quite catch what's making him feel like accepting your confession, That's why he accept
But he can't show any affection since he doesn't feel anything related to that...yet.
Sure he talorates you around him...Despite your affection..it didn't budge him at all!
He's always cold toward you...and still are...maybe he'll warm up eventually.

Your goal is to make him fall in love harder for you.