Aka-chan to Boku

From Viz:

Young Takuya has it tough. After his mother passed away it has been his job to take care of his baby brother Minoru while their father, Harumi, works the long hours of the Japanese "salaryman." Takuya must sacrifice the playtime usually associated with childhood for the responsibilities of an adult. Cooking, cleaning, sewing and scolding are all now an integral part of the young boy's life. "All work and no play" has Takuya incredibly frustrated and resentful of his little brother. Will Takuya find it in his heart to love the brother who is causing him so much grief?!

Baby and Me received the 40th Shogakukan Manga Award for shōjo in 1995.

Included one-shots:
Volume 2: Time Limit
Volume 4: Secret Boy ni Tee Dasuna!!
Volume 6: Baka de Karukete Wagamama de
Volume 15: Natsu to Kimi no Irradiation