Tatsuya story which begin after the Ten Master Clan Conference when he got called by Yotsuba Maya to visit Yotsuba Residence, will tell Tatsuya's as a member of Yotsuba from my perspective, probably will show a lot of characters, start before Tatsuya's 3rd year at Magic High School, pairing undecided, you can suggest the pairing that you want with the reason why to me hehe