iwanttousenotosanscjkjpfont is a free Chrome add-on developed by Kerus Ashe. It falls under the category of Browsers and specifically the subcategory of Add-ons & Tools. This add-on allows Korean speakers who understand Japanese to change the font set of their system to 'Noto Sans CJK JP'.

For Korean speakers who also speak Japanese, dealing with Korean and Japanese Chinese characters (kanji, hanzi, hanja) can be tiresome. The default system font may differ from the Japanese Chinese characters used in Japanese, using Korean Chinese characters instead. With iwanttousenotosanscjkjpfont, users can now see Chinese characters in Japanese and avoid the use of Korean fonts like '굴림', '돋움', '바탕', and '궁서'.

Before using this add-on, it is important to note that users must first install the 'Noto Sans CJK JP' font on their system.