Kokoro ni Hana wo!!
From Saigo no Shou:
Five orphaned boys are now living their separate lives, when an accident befell on their old foster parents, prompting Hanayagi Sakura--a naive, 16 year-old, happy-go-lucky boy--to re-open the flower shop their foster mother loved so much. Will he succeed in bringing the family together and save the flower shop from mortgage debts? Kokoro ni Hana wo is family-genre manga that will surely touch your heart!