A Galaxy Next Door

Ichirou Kuga is a comic artist who raised his younger siblings, Machi and Fumio. In the middle of his deadline, a new assistant named Shiori Goshiki suddenly appeared and helped Kuga to meet the deadline. Shiori fell asleep due to exhaustion, and Kuga found a thorn-like object in her body. When he tried to pull it off, a vast universe appeared in his mind. Who is this mysterious assistant?

After working late to help Ichirou, Shiori returned to her accommodation. Machi and Fumio excitedly shouted, "We're having a barbecue tonight!" Perhaps due to being too tired, Ichirou fell ill with a fever. Because of the "marriage contract", he began to feel sick as soon as he was away from Shiori. Shiori felt guilty and decided to move to Ichirou's apartment.

How far can Ichirou and Shiori be from each other? They start experimenting with the "marriage contract." During this time, Ichirou's childhood friend Momoka visited him. Shiori became excited upon learning Momoka is her admired comic artist, but witnessing the friendly interaction between Ichirou and Momoka, she starts feeling jealous for the first time.

After confessing her feelings, Shiori finds her feelings for Ichirou grow stronger. Heavy rain spoils Ichirou's trip to the zoo with Machi and Fumio. Shiori offers to look after Machi and Fumio. Machi suggests playing the tarot cards Ichirou made for her, but they accidentally get torn. Shiori heads to the library to find out how to make tarot cards. Worried about her, Ichiro goes too.

Ichirou, Machi, Fumio, and Shiori visit the zoo together. Ichirou, who just confessed his feelings to Shiori, is unsure whether to tell Machi and Fumio about their relationship. They had a great time at the zoo, and Ichirou told Machi and Fumio about his relationship with Shiori. When Machi asks Shiori what she likes about Ichiro, she begins to wonder what Ichirou likes about her.

Ichirou invites Shiori on a date, but she feels down after struggling with her work as an assistant for another comic artist. To cheer her up, Ichirou takes her, Machi, and Fumio for dinner. The first-time experience at a barbecue restaurant moves Shiori. Born and raised on an island as a princess, she becomes aware of the difference between her and ordinary people.

Ichirou, Machi, Fumio, and their cousin Chihiro visit their late father's grave. Unexpectedly, Shiori goes with them. After this, they have a picnic together. Although it was a happy time, Machi and Fumio cried because they miss their father. Shiori also recalls her late grandmother. Before leaving, Ichirou visits his father's grave alone. Shiori sees the loneliness in his eyes so she follows him.

Ichirou and Shiori finish their hectic year-end work and find themselves surrounded by the festive atmosphere. Ichirou invites Machi, Fumio, Shiori, Chihiro, Momoka, and comic artist Sano to his apartment for a Christmas party. After Momoka and Sano leave, Shiori, Machi, and Chihiro have their own gathering, where Shiori decides to reveal her true identity.

While Ichirou is still dwelling on his Christmas date with Shiori, Shiori feels sad due to the call from her mother back home. In January, they win a hot spring trip and excitedly go with Machi and Fumio. During the trip, Shiori tells Ichirou about her decision to leave the island to rebel against her mother. Shiori's mother never stops calling Shiori.

Shiori's mother goes to Ichirou's apartment with her husband and entourage, intending to bring Shiori back to the island. The next day, Shiori and Ichirou talk to her parents, but her mother refuses to listen. On a sudden impulse, Shiori told her mother about her marriage contract with Ichirou. Angered and hurt, Shiori's mother leaves, with Ichirou chasing after her.

On the eve of the annulment ceremony, both Ichirou and Shiori are restless. Ichirou fears his memories and feelings for Shiori will disappear when the thorn is removed. As the ceremony begins, they both question if their feelings are genuine or just a result of the marriage contract. When the thorn is finally removed, their memories of their time together begin to distort and fade.

After the ceremony, Shiori and Ichirou return to their old life. Shiori runs into Chihiro while shopping for new clothes for a date. On the way home, she finds Machi and Fumio at the park. Worrying about Ichirou, Machi refuses her friend's invitation. To create happy memories with Machi and Fumio, who rarely played with friends, Shiori comes up with a plan.