NATSUME YUUJINCHOU/BOOK OF FRIENDS - Looking for chapter/special???

Hey--I remember reading this chapter/special in Nastume Yuujinchou where a water or lake yokai/spirit/something gives one of Natsume's ancestors the family name of Natsume BUT I can't find it anywhere. I don't know if it was a fever dream, but I would really like to re-read it and even after skimming through all the chapters I can't find it. Does anyone know if it exists/what chapter it is? ╥﹏╥
2021-08-26 18:15 marked

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