It’s called Komei’s Channel
The creator is a native Japanese speaker, and he does videos in both English and Japanese, mostly talking about quirks of the Japanese language.
His most viewed videos are ones where he does stuff like try the JLPT or Japanese Duolingo, but for me those were actually some of the less interesting ones. Most of his videos have less than 1000 views, so I’m guessing many people here might be unaware of his channel.
Here’s a selection of the different types of videos he makes.
Discussion of the use of クレーム in Japanese and how it differs from English
Discussion of the word 無駄足 and some of its synonyms
How to use the word まくる (do over and over, go crazy doing) to attach to words
A summary of various first person pronouns
A discussion of the kanji 峠 as part of a series on 国字 (kanji invented in Japan)
A series on onomatopoeia