Death March kara Hajimaru Isekai Kyusoukyoku (WN) - Side Story: Kishresgalza Clan

Kenichi Yamada was a 35-year-old salaryman. As a hardcore game enthusiast, he was saddened by the modern trend towards casual games.

So, when a site claimed to be “for people who like to do things the hard way,” he just couldn’t resist. Thus, he was reincarnated into another world as Allen, playing on Hell Mode.

This is fantasy light novel about Allen’s journey as a summoner.

Reincarnated as a serf, he starts from nothing.

His journey begins with absolutely no knowledge of the world around him, just like those games he played 10, 20 years ago.

He, without doubt hates her.
What did she do to deserve his hate?
The person who she treated well like a brother did not even bother to notice it...

Years passed…

He needs to get married.
He needed a wife.
So she offered herself.
It was a marriage that will benefit both parties he said.

A side story series featuring the girls of Kyoukai Senjou no Horizon.

In the winter of Taikang Year 3, a girl pays a visit to her future in-laws, the Ning Family of Beiliu, Yangcheng.

After her engagement was denied, the girl decided to hang herself in front of the Ning Family to show them her sincerity.

When the girl who had died opened her eyes once more, many people’s fates were changed forever.

- Description from Novelupdates