Here’s the catch: Most kanji have additional possible pronunciations, a quirk related to Japan’s adoption of the Chinese writing system more than 1,500 years ago.

Source: https://www.nytimes.com/2023/12/01/world/asia/japan-baby-names.html

His last name is written 愛城, with the kanji "ai", meaning love; however, the variant of love in this case isn't used casually.

Source: https://gamerant.com/100-girlfriends-the-first-five-girlfriends-name-puns-explained/

The rest of their names don't necessarily relate to the 無 or 有 kanji.

Source: https://www.cbr.com/demon-slayer-the-mu-in-muichiro-explained/