'Rendaku': sequential voicing, which governs how to pronounce the consonant of the 2nd part of a compound word (formed by putting two whole words together). So "k" becomes "d", "t" becoms "d", "sh" becomes "j", "h" becomes "b". The name of the brand "tokidoki" is governed by this. It's actually "toki" + "toki" = tokidoki. So the word "sometimes" is formed from saying "time time", but changing the first consonant of the second word so you understand it's a compound word. Like if saying "timedime" meant "sometimes" in English.