Chibiusa's affections come into conflict. Despite being self-aware of the fact that Usagi Tsukino and Mamoru Chiba are her biological parents, she does not immediately identify them as such, instead suspiciously viewing them as strangers who look like them. There is evidence that Chibiusa has a hard time identifying Usagi and Mamoru as being her parents since she sees such a sharp contrast in personality between their present and future selves. However, it is worth mentioning their forms King Endymion and Neo Queen Serenity are far in the future, leaving enough time to mature. She also reacts differently toward Usagi and Mamoru than she does towards King Endymion and Neo-Queen Serenity, being more respectful to the latter but more spontaneous to the former; it is not clear if she prefers one set over the other. However, she always calls her teenage father Mamoru as Mamo-chan (in the 20th century), an affectionate nickname by Usagi, and has an innocent crush on him, much to Usagi's fury.