Itai no wa Iya nanode Bōgyo-Ryoku ni Kyokufuri Shitai to Omoimasu - Chapter 102

While the demons were rising, mankind was about to become extinct. Six temples rose and protected the last territory of mankind.

In ancient times, there were seven types of evil thoughts, each of which possessed the power to confuse, and muddle, people’s hearts. Every single person that came into contact with one of the seven, would inevitably undergo a sudden change in personality and temperament, and commit the unforgivable crime of murder.

Determined to rid the world of these seven evil thoughts, Lao Zi forced the seven evil thoughts into seven separate bamboo strips and secured the opening of such bamboo strips with the Phoenix Lock, and, in so doing, finally succeeded in sealing the evil bamboo strips.

But who would have thought, that the evil bamboo strips would, in due course, reappear on the surface of the Earth……

- Description from Novelupdates

Another entry in what you can call the Proto Harem Series: the books written before the Harem Series that take place in the same world.

It’s about a swordswoman whose student is captured, so she goes to rescue her.

Utsuro no Hako to Zero no Maria, or The Empty Box and The Zeroth Maria, tells the sinister story of Kazuki Hoshino, who is almost madly attached to his everyday life, and his antagonist Aya Otonashi, who suddenly transfers into his class—for the 13,118th time. She majestically announces to “break” him, without paying heed to anyone else around them.