I think I got it. Its Alphonse Mucha. It was driving me mad cause I felt like I saw it somewhere before (I am fan of his).
The Japanese fits (堺アルフォンス = Some Kanji Alphonse, they are treating F for Ph, phonetically the same characters) DeepL kinda even agrees.
View attachment 2484944
He is know for drawing a lot of women open sundresses like that and while I dont think its 100% exact match, I think I found the reference one.
View attachment 2484950
Notice the distinct shape of flower petals, exactly four each in the enemy and painting (harder to see there) both.
So they are providing some variation or shortening of Alphonse.