Long story short: Tsuki ga Kirei is a love story between a girl in track and field and a boy writing a novel. (As always I’m writing this after three episodes, so there will be spoilers for those. I’ve started adding mouse-over translations for Japanese kana/kanji, so check those out as well.)
The girl’s name is Mizuno Akane (Akanecchi to her friends) and the boy is called Azumi Kotarou (Kota to his). They’re in middle school, in their third and final year. They are placed in the same class for the first time and have never talked to each other. Until they meet at a restaurant, when celebrating the beginning of the school year with their families. はずかしい！
Back at school, the sports festival is coming up. The two leads are in charge of the equipment along with a large part of the track and field club. Kotarou, being a library assistant, is an outsider, while Akane has friends all around her. But they exchange LINE IDs.
The second episode is all about the sports festival. While Akane is training for that and a race that’s soon after, Kotarou submits two stories to competitions. During the festival, Hira Takumi is brought to our attention as Akane’s potential suitor. I don’t think Akane gets it, though. (Her girlfriends support him from the shadows though.)
The third episode starts with midterms. After that, it’s time for Akane’s race and soon after the school trip. Their schoolmates are hooking up left and right. On the day of the race Kotarou is at the shrine, “community stuff” he says. He’s hypnotizing his LINE. Akane sets a personal best! And her battery dies. The third episode ends with a cliffhanger of sorts. きになります！