Yoroshiku Brother?

is the oneshot written by Junko Ike.

Summary
When 15-year-old Hiro Mayumi's mom remarries, he soon discovers that is he is now a big brother to 5-year-old Yuuki. When Hiro's mom and stepdad go to Hawaii on their honeymoon for a week, Hiro must now take care of Yuuki and cope with his new family situation.

Characters

 * Hiro Mayumi
 * Yuuki Mayumi

Trivia

 * This is Junko Ike's debut work