[Shameimaru]

Thank you for your quick answer, apparently it was simply a transcription mistake made by myself ...
It really was the て/で that prevented me from understanding.

To be honest, I didn't even noticed the missing ん as it didn't "changed" the whole meaning (自己研鑽 was written as 自己研さん).

The book is actually 「Alternative Facts in Eastern Utopia」, the last official book about Touhou Project, a famous Japanese series of video games.

Ibaraki Kasen and Seiga Kaku are two female hermits from this series.
Also the series is known to have "almost" only female characters with human form representing different youkai. (It's not really classed in the "classic" Asian stories).

The error come from the fact that I am copying myself the lines from the physical book, and it didn't came to my mind that I could have made a mistake at this moment ...

PS: Your message clearly answered my question, but I don't know if their is a way to mark the Thread as [Answered]