Chapter 1:

After the dead of her mother,

the six-teen-year-old girl Asuka Higuchi moved to Tokyo to look for her father.

Using a motorbike without a helmet, she was chased by a police. Then she ran across a guy who was dragging a girl, who's later found out as his little sister.

Rescuing herself, she joined them to their house and asked for Sudou's home address. In surprise, the guy said, that it's Sudou residence.

He's Manato Sudou (15) and her sister's Kazusa Sudou (14).

Asuka explained them that they were relatives,

and that she's looking for her father (their father).

But Manato and Kazusa don’t trust her.
How can they believe the words of an unknown girl who says that she's their oneechan (older half-sister)?

They started to live together, but Manato and Kazusa's indifference towards Asuka didn’t become less.…

Asuka went to the same school with them and oneday she helped Kazusa, who was bothered by some guys. The boss of the gang was Tooru Hayami, who was in love with Kazusa.
Manato had warned her not to be involved with Hayami and his gang.

But Kazusa, who hated anyone who tried to be near her big brother, instead of thanking Asuka, told Hayami: "Yeah, Hayami, do whatever you like with this idiotic girl! If you can arrange so I won't see her face again, I'll go out with you!"

A boy ran to tell Manato that a girl was fighting with Hayami and his gang!
Manato fought Hayami back, but his ankle was hurt, he couldn't even move....

Asuka decided to beat Hayami. ^_^

She did it and won Manato's trust.

ASUKA HIGUCHI

MANATO SUDOU

TOORU HAYAMI

Chapter 2:

Kazusa was always a problem to Asuka... both at home and at school....

After the fight, Hayami fell in love with Asuka! On the other hand, Kazusa planned a trap for her. Asuka must defend herself from a gang of hooligans. She beat them! But then everybody knew she's a hooligan too!

She ran away. Manato chased her. He hugged her to give relieve.... For the very first time, he called her "oneechan".

Crying... Hayami came to thank her.

She won everybody's heart, except Kazusa's....

Chapter 3:

Then came a pretty girl named Youko Kamiya, a very strange girl who always arrived from the sky on Manato (see the pic... ^^;;;), who was the captain of the gymnastic club. She's in love with Manato, who felt terrorized by her....

Youko and Kazusa used to quarrel about Manato, leaving Asuka amazed.

But Youko considered Asuka as her rival in sport and love!

Asuka must take part in a competition instead of Youko, because the girl was "injured"...
But on the day of the competition, Asuka was kidnapped!!

Manato and Hayami saved her....

(though personally I think she could save herself...... :P)

They bring Asuka to the competition by car.

0.0

The first volume of Shishunki Miman Okotowari ends with the arrival of Manato's grandpa,
an old man, a little... maniac!! Especially with Asuka.... 
His arrival meant doubtful and disorder situation....

Additional images (full size):

Lia Cyntia

Aya Mikage