Moongetsu
Because as Tatsuki already knows Ichigo, she knows he wouldn't give a direct answer to her about this kind of matter, especially considering his protective nature. Since everyone started attending Karakura High School in April, Yato and Tatsuki wouldn't be so 'strange' to each other anymore. At most, they're just classmates, but because Yato is involved in things, Tatsuki simply assumed that Yato wouldn't hide things from her.
I hope there are some new scenes as well. So far, only the cannon events are happening and mc is being relevant by hanging around Ichigo. And since Rukia's Gigai stays with Yato, it should make Ichigo weaker in the long run. I hope mc will take the lead in the future and he will be at the center of things as any decent mc should be