無限論の教室

Wakana Shiono, Tachibana Tachibana, and Masanao Gojo are ordinary junior high school students who are about to graduate in March.
Except for the fact that Lixia's birthday is "February 29th".

That year without February 29th.
Instead, Wakana and Masahisa frolic to celebrate on the 28th.

"... What do you think it feels like you don't have a birthday?

"
As if that word was an opportunity, we would step into an extraordinary event.

"It's" yes "but" not "-it's strange, isn't it?"