Giri☆Giri Sisters

Family Planning begun out of duty
Immediately after beginning to live on his own, the protagonist Kaoru's home is destroyed in a fire.
Gazing, dumbfound, as his apartment goes up in flames, someone calls out to him.
"Um, excuse me?"
He turns towards the voice with a sullen expression on his face, only to find himself looking at his dead mother....
"Um... You're Kaoru, right?"
This was the first meeting of Kaoru and his aunt.
The sudden sister-in-law

[From DLSite English]