熱中　concentrating

にこさん毛づくろいに熱中中
Niko is concentrating on grooming.

なでしこさんとゆずくんケンカに熱中中
Nadeshiko and Yuzu are concentrating on fighting.

ばにらさんお金に熱中中(> <) Banira is concentrating on money >.<
(This plastic box is a donation box)