this wasnt the end i think should happen but i actually really like it. i did think she deserved to be in a non harem manga, so her having a happy ending is nice to see
@Servitude that's an Asumi-route-specific event, and flashback-exclusive. As for its timeframe, Nairyuki is holding his HS diploma, so probably right after the graduation ceremony, in front of the school?
Now, if you want to know when/how they got those tickets, that would be chapter 126.