College student Miyako Hoshino is quite shy around other people. She mostly spends her time in her room making cosplay outfits. When her fifth-grade sister Hinata brings her classmate Hana Shirosaki home, Miyako instantly becomes captivated with Hana's cuteness. Miyako tries to do various things, ranging from making Hana wear cosplay dresses to giving her sweets. This gives Hana a bad impression of her at first, but Miyako will do anything to grow closer to the angel who has descended before her.

Hana, Hinata, Noa, Koyori, and Kanon are always good friends. Today, they are having a friendly sweets party at home with Miyako's homemade sweets! The flower-shaped cookies look just like the hair ornaments worn by Hana. The hair ornament was a precious treasure that Hana received from her grandmother when she was little, and everyone was intrigued by the story. And as practice for the school trip, they decide to go visit Hana's grandmother's house...! The first outing for everyone is about to begin. (Source: Crunchyroll News)

Hinata Hoshino, Hana Shirosaki, and Noa Himesaka are off to the countryside for a camping trip. At Hinata's behest, her elder sister, Miyako, reluctantly tags along. Seeing how gloomy Miyako is, the trio do their best to get her to enjoy herself too. Besides the camping trip, Watashi ni Tenshi ga Maiorita! Special contains three more short stories of the girls. Although their lives seem normal, one thing is certain: there is definitely no shortage of cuteness here!

Kae Serinuma is a very kind second-year high school student and a devoted otaku. A little known fact about her, though, is that she's obsessed with BL, or Boy's Love. Serinuma can't help but to fantasize about her male classmates falling for each other and enjoys imagining them together. A more known fact about Serinuma, however, is that she’s noticeably overweight. While watching her favorite show one day, Serinuma witnesses the death of her most beloved character. Utterly depressed, she can't muster up the energy to eat her meals, let alone attend school. After an entire week, she finally recovers. But now there's something unusual about her—during the time she refused to leave her room, she ended up losing a large amount of weight and has somehow become strikingly beautiful! Now catching the eye of everyone who sees her, she finds herself at the center of attention of four boys she has always known at her school. Though they all wish to spend time with her, Serinuma would much rather they spend time falling in love with one another. How will Serinuma deal with the four boys pursuing her BL-obsessed self?