Ch 4 when Yuma suggested a bathhouse and cyber cafe for Kai to wash up cus he thought Kai still lives w his parents AND wanted to respect his boundaries as Yuma acknowledges being the older/mature one. And only after Kai hints at going to Yuma's house does it click to him like OMG THAT WAS SO CUTE
at first i thought this felt a little too yandere 1 sided for me... and then i realised they both freaky so it worked out in the end