Kusakabe Renji, a young man working at a game centre, sees an English girl named Lily Baker playing a crane game on Valentine's Day. Seeing her fail repeatedly to win a prize, Renji can't help but take action. The day after Lily finally gets her plushie, Renji receives an unexpected message from her that reads, "Be my valentine!" What started as a misunderstanding leads to cultural exchange!
While working at an arcade, Renji strikes up a friendship with an English girl who can't speak Japanese.
Renji's sister Aoi asks him to make her a "game center pro" before she visits the arcade with her friend Lily.
After Renji and Lily go on their date, Aoi informs Renji that she invited Lily to come over for a study party.
Lily's jealousy is ignited when a pretty girl who visits the arcade turns out to be Renji's college classmate.
When Lily forces Renji to walk her home on a rainy day, the two happen to run into Lily's intimidating father.
A new challenger shows up at the game center to compete for Renji's attention, but Lily steps in to stop her.
Hotaru checks whether her classmates are engaging in meaningful activities in the arcade.
Lily invites her school friends and Renji to her birthday party and shows them how people celebrate in the UK.
As Lily and friends enjoy their summer vacation, new and unique guests start to appear at Renji's game center.
The game center holds an Otokogi Koala Fighters knockout tournament that attracts a wide variety of players.
Lily, Karin, and Hotaru join Renji and Aoi on a trip to visit their grandma's home up north in rural Tohoku.
With Grandma's love story still fresh in their minds, Lily and Renji face up to their feelings for each other.
