Thread:CureHibiki/@comment-32907504-20171010091034/@comment-30795786-20171010113703

CureHibiki wrote: I learnt at school tho [...] For heaven's sake, people, stop playing the grammar police when you have no idea what you're doing.

Both "Aqours" and "Printemps" end in a silent "s" (i.e., it is not pronounced), so you need an extra one after the possessive apostrophe. For a similar reason you would use the indefinite article "a" instead of "an" before, say, the word "unit" (e.g., a unit of measurement), since the latter begins with a consonant sound ⟨j⟩ (even though "u" itself is a vowel letter). See also Thread:52692.