Lol, the moe style makes them look so childish already that I confused the flashback with our time, thinking "oh, so now she's talking openly with Kai again?"
While i understand that this is the series concept, when Bochii says it has been 3 years it really fells like the author pushed this too much, i´m more worried of Nako not passing the exam than Bocchi reunion with her old friend.