Well, Mika is just acting separate, your interactions include seeing her through the day, seeing her dressing in the morning and udressing in the evening. Also there is a chance to have sex with her in the evening and at the beach you can feed her icecream. Like this
well then the beach and Icecream dont work, I tried it at varios times of the day and nothing ever happens
also the belly sizes are highly fluctuating, sometimes they just go flat again and mika seems to be completely stationary, she never gains anything except the stomach and bowel capacity, she always has the same sprite and 53kg weight
I dont want to fuss so much, but for a game you have to pay for I think it would be nice to have atleast a bit of content and an optional guide