This article is incomplete. Please feel free to edit this article to add missing information and complete it. Specifically, it needs the Japanese release date.
Only Comes Once a Year (年に一度のお楽しみToshi ni Ichido no Otanoshimi?) is the 5th chapter of the 7th volume and the 51st chapter overall of the Attack on Titan: Junior High manga, written and illustrated by Saki Nakagawa.
Levi's birthday is coming up, but the Survey Club are told that he does not like birthday parties due to the trash and garbage that comes from them. How will the club celebrate the occasion without causing a mess?
Summary
When looking at a calendar during a Survey Club meeting, Eren notices that Levi's birthday is coming up soon; while Sasha and Armin discuss what to do to celebrate, Eren proposes a large party with streamers and several birthday themed items to try and kill the Titans. Unbeknownst to him, Levi heard the entire thing and mutters how they must now be prepared for the consequences.
Eren tries to backpedal, but Levi leaves without saying more; Petra mentions how Levi hates birthday parties due to an incident the year before. When her, Oluo, Gunther and Eld tried to throw a surprise party for him, Levi could only notice the mess made from the streamers and treated them more harshly than ever. Deciding on a new strategy, the group spends the rest of the month brainstorming different ideas to mark the occasion.
On Levi's birthday, he gets an invitation to a party in the Survey Club room. Disgruntled by this, Levi still decides to show up. Expecting a repeat from last year, he is taken by surprise by how the room has been redecorated for a formal setting. Taking some tea, he sits in an armchair and over the next several minutes silently remarks how it is indeed a nice change as the other Survey Club members present him unwrapped presents to avoid any garbage or clutter.
When they bring out the cake, Levi immediately begins glaring and mentions how it is ruined; confused, the first-year students realize they did not evenly space out the candles on Levi's cake. He angrily swats the cake but a slice of cake lands on each of the plates; while Levi does express some annoyance on the candles remaining on the floor, he says he will overlook this little bit of trash for the day. Unfortunately, as Eren cheers their success, his piece of cake falls to the floor and the entire club is forced to spend the night cleaning as a result.