Yu and Shinji are both introduced in the first episode of the anime as Pro Heroes Mt. Lady and Kamui Woods. They both fight the villain that had appeared in the city, but Yu, who is making her debut as a hero, ends up getting all the credit for taking him down, which Shinji is not happy about. They do work together fighting villains during the U.S.J incident, and as guards during U.A.'s Sports Festival. There, Yu uses her good looks to get free food, and Shinji critiques her for having no shame. She later teases him for having a quirk similar to one of the U.A. students
Yu and Shinji take a car together to the League of Villains' hideout. Near the end of the fight, Yu is knocked unconscious, and Shinji rescues her, telling her she did a good job. They are good friends after this, and form a team with a fellow Pro Hero Edgeshot, dubbed 'The Lurkers'. During the Hero Billboard event, the whole team is present, Shinji being in the top ten, and Yu is disappointed she hasn't reached it yet. Interviewers then approach Yu about Shinji, and she says she's learned a lot from being on the same team with him. She is then asked about the rumors of them dating, but simply smiles and declines to answer.
The Lurkers eventually take on several work study students, including the U.A. girl Yu had mentioned to Shinji. During the Paranormal Liberation War, they take on Gigantomachia together. They both show immense concern for each other. Shinji yells for her when she is tossed to the ground, and Yu worries for him when he is knocked out by Midnight's quirk. Despite being knocked down the two get back up to stop Gigantomachia, with Yu grabbing his legs while Shinji rides on her back as he attacks the villain with his quirk.
- Mt. Lady – “Being on the same team as Kamui gives me a lot of encouragement.”
- Interviewer – “What do you say to the reports of you two having an alleged love affair?”
- Mt. Lady – “No comment.”
- — Mt. Lady being interviewed about her and Shinji in chapter 184
This pairing is the most popular for both characters, due to how often they are seen together. Fans enjoy the growth of their relationship from rivals to close friends, having formed a team together and caring for each other greatly. The ship was only further encouraged upon the revelation that in-universe there are rumors of them dating, which is non-existent for any other Pro Hero ships. Yu is often portrayed as being flirty and teasing towards Shinji, which he finds both annoying and endearing.
On AO3, the ship has 53 fanfics, while FanFiction.Net currently has two fanfics. Along with having a reasonable size fanbase on Tumblr and DeviantArt.
- Yu's Relationship with Shinji on My Hero Academia Wiki
- Shinji's Relationship with Yu on My Hero Academia Wiki