Became Dazai's Biological Father at the Beginning

I will refuse his father once he travels through time and becomes a child. Until I heard this child's name - Shuji Tsushima 1. The protagonist, the flower grower, is dressed as Dazai's biological father as per the title. 2. Imagination and passion during chatting 3. Yang Zaiwen, no other CP except official match 4. The protagonist's abilities are self-designed and are not disqualified from the world. 5. Think of adding more Concept: Raising children is a technical job