The Japanese international joins the Club from West Ham United, where she enjoyed a hugely successful 2021/22 campaign.
Hasegawa is Gareth Taylor’s seventh signing of the summer, committing her future to the Academy Stadium until 2025.
Reflecting on her move, she said: “It’s been a huge dream of mine to come here and play football, so I’m glad to make the move.
“During the last season when I played against Manchester City I really liked the feel of the place, so when I got the opportunity to join, I immediately said yes.
“People tend to see me attacking the most, but I also want them to see me defending, and my unpredictability.
“Even though I’m small, I’m a strong player and I want them to see me showing that during the games.”
Hear Yui’s first interview as a City player in full via the video above…