From Wiktionary, the free dictionary
From Japanese 清楚 (seiso, “clean, tidy”).
seiso (comparative more seiso, superlative most seiso)
- (VTuber fandom slang) Pure, proper, and wholesome, especially in the sense of being non-sexual.
2020 July 31, @AlValence, Twitter[1]:I thought Pekora was a pure seiso girl. How could she retweet this?
2022 November 14, /u/yuviia, Reddit[2]:i’ve been streaming for a while and i’m pretty seiso. i don’t enjoy top/bottom jokes or being lewd in general although being slightly sexy is okay.
seiso
- inflection of seisoa:
- present active indicative connegative
- second-person singular present imperative
- second-person singular present active imperative connegative
seiso
- Rōmaji transcription of せいそ