Kasumi Kishimoto, 15 years old, is a freshman attending to Meijou High School from her aunt's house, which runs her boarding house. Her life has begun with her natural-blurred aunt and the four unique boarders.

Kasumi gets entangled by cheering team members at Meijou High School. At that time, Yusaku Takasugi, a boarder, appears. Yusaku is a friend who met a naked one in the bath!?

Kasumi and Yusaku Takasugi become classmates. Kasumi says she will join the track and field club, and Yusaku will join that cheering squad. Yusaku wants to support people who work hard!

Yusaku is ordered by the cheerleader Sakamoto to bring Kasumi, but he gets feverish and collapses. Yusaku who saw Kasumi being taken from the health room...

Is Sakamoto, the cheerleader, really bad? He had a cute hairpin labeled "Michiko". It's something strange.

Kodama, the person Sakamoto caused the violence, called Sakamoto again. Kodama seems to be the lover of Michiko Takagi, the owner of the hairpin that Sakamoto had.

Sakamoto filed a dropout notice, and Yusaku, who was entrusted with the group, was enthusiastic. The favorable Keiko's older brother Seki, the ace of the baseball club, asked him to make the baseball club even more exciting.

Yusaku invites Kasumi to the manager of the baseball club, but she didn't feel like devoting herself to athletics. However, she looks like Yusaku who supports people.

Kasumi, who became the manager of the baseball club, puts thirst on the members. Such a baseball club has a chance to play a practice match with a prestigious school that is a candidate for victory.

Yusaku decides to take the place of the injured center. He's trying hard, but it doesn't work. However, Seki knew the nature and guts of Yusaku.

Keiko is worried about the relationship between Kasumi and Yusaku. She takes the courage to invite Yusaku to a concert. Kasumi devotes herself to her housework, but she becomes concerned about Yusaku.

The combination of summer qualifying tournaments has also been decided, and the practice of the baseball club has also become enthusiastic. It's the last summer for captain Seki... he had a special thought.

It's the first round of the summer Koshien qualifying tournament. Kasumi encourages the nervous members. Her lover "Katsuhiko" will return from America during the summer vacation.

It's raining on the first round. The Meijou baseball club, which defeated Torijou High School, was enthusiastic about the second round. At that time, Yusaku was asked by Mikimoto about his feelings for Keiko.

It's quarterfinals for the members who are proud of their time. Kasumi and Yusaku don't talk about each other, but they bother each other. Kasumi takes care of Yusaku who was injured in the game all night.

It's finally the semi-final. Kasumi worries about Yusaku who behaves well. Her last night with Yusaku flickers during the phone call from Katsuhiko. Yusaku's appearance is still Kasumi.

Finally advanced to the final! Yusaku was participating in the cheering party, but he's dying for Kasumi's lover "Katsuhiko" to return to Japan.

In the middle of the final match, Katsuhiko suddenly appeared. Yusaku, who was looking at the joyful Kasumi from the mound, missed the ball he could get.

They lost the final game, but they have no regrets. They have a disappointing party with the usual noodles. However, Katsuhiko also participates there. Katsuhiko is conscious of Yusaku to Kasumi who praises Yusaku.

It's summer vacation. The aunt drove to the sea and everybody enjoyed being divided into couples. Suddenly, a girl named Maria, appears in front of Yusaku.

The aunt invited Shinichiro, who had become close to him at the beach, to a barbecue. His daughter who appeared with him was Maria who tried to kiss Yusaku.

Yusaku and the other boarders all went home, and Kasumi was alone with Katsuhiko. However, she is worried about Yusaku.

Katsuhiko, who declared his rival to Yusaku, "I will propose to Kasumi," has to go back to America. What is Katsuhiko who talks about his passion for baseball?

After returning to America, Katsuhiko recalled the days he spent with Kasumi and his encounter with Yusaku. Kasumi's feelings for her lover are beginning to lean toward Yusaku.

On Sunday, when the summer vacation is over, Kasumi, who is awakened early in the morning due to the commotion of the housemates, is in a bad mood and collided head-on with Yusaku on the stairs! Why does she get mad?