“relation / to be in charge” in Japanese is 係, read kei, kakari (けい, かかり). It is a Grade 3 Kyōiku kanji, taught in year 3 of Japanese elementary school, and appears in words such as 関係 (relationship).
What does 係 mean?
掃除の係になる。
Same sound, different character — the classic trap. Compare them side by side: