Happy Sugar Life - Season 1

Shoko is surprised to hear that Satou has decided to give up fooling around with guys and start living together with the person she loves, a mysterious girl named Shio. Satou starts working more to cover the expenses of her new life with Shio. However, an incident happens at her new job.

Satou is holding a trash bag covered in blood. She tries to throw it away in the river, but senses someone nearby. The next day at school, the class president, Kitaumekawa, worries about Satou and tries to talk to her. Meanwhile, Asahi is handing out flyers around town looking for Shio.

When Asahi gets attacked by a group of thugs, Satou and Mitsuboshi protect him. Satou senses that Asahi and Shio are connected to each other through a special relationship, and is almost overcome with anger. Meanwhile, Shio starts to worry when Satou is late coming home, and leaves the apartment to search for her around town at night alone.

Shio runs into Mitsuboshi on town at night, which reawakens memories of her painful past. Shio's father was abusive towards his wife. Shio sees an illusion of her mother, who tells her that she'll never forgive Shio. Shio passes out in a park, and thugs creep up around her.

Sumire, a coworker at Satou's job, is interested in Satou and admits that she peeked at Satou's resume. Sumire becomes suspicious that no one is actually living at the address on Satou's resume. Meanwhile, Shoko goes to Mitsuboshi's place to visit him, but discovers something shocking in his room.

Shoko starts to get suspicious about Satou, and runs into Asahi passing out flyers. Satou says that she has to go to Mitsuboshi's place to deliver a notebook with a message from work, but when Mitsuboshi opens the notebook, he finds a message asking whether he wants her to let him see Shio.

Satou and Shoko head to the apartment where Satou says she lives. As soon as they step out of the elevator, they run into two police officers, who tell Satou to knock on the door. Someone opens the door from inside...

The apartment where Satou and Shio live, Apartment No. 1208, used to be the home of a male painter who lived alone. Satou used to be his model, and would visit his apartment every day and have conversations about random things. However, one day...

Satou gets Mitsuboshi to agree to help her by offering to let him see Shio. Mitsuboshi contacts Asahi and tries to get him to leave town to get him away from Shio, but Asahi gets suspicious. That night, Asahi reveals his feelings for Shio to Shoko.

After killing Shoko, Satou returns to Apartment No. 1208, and passes out into a deep sleep. Shio doesn't know about what happened, and starts thinking about her mother, Yuuna, who left home and abandoned her. Shio's father was always violent towards Shio's poor mother, who was scared, sad, and also very kind.

Shoko had sent a photo of Satou and Shio to Asahi right before she was killed. Asahi captures Mitsuboshi and forces him to reveal the location of Satou's apartment. Satou makes a vow to Shio to fight together, and heads to Apartment 305, where her aunt lives.

Satou and Shio spend their last night in Apartment No. 1208. The two girls wear matching rings. Satou tries to bury everything so that they can enjoy a brighter future. Meanwhile, Asahi has something he has to tell Shio, and searches for the two girls.