Sure there is. First four letters, right there... See?
Actually O-Sensei never used the word "harmony". He used a lot of really esoteric Japanese words and often used them in curious ways. "Harmony" *is* one common way to translate "ai" but it is incomplete and the word "harmony" carries a lot of connotations that he might or might not have agreed with in his usage of the term.
Sounds nicely philosophical, however.
Alas, Japanese is not my forte. So I'll bow out now.
in Japanese or Chinese means "to blend", "to combine", "to mix".
in Japanese has the same pronunciation as "Love" in Japanese.