Hiragana is the basic Japanese “alphabet” system. It covers all the basic syllables.
There are 46 letters, but there are 5 “root” sounds. A (aah), I (ee), U (oo), E (eh), O (oh). The other letters (aside from ん) have the same vowel, but an added consonant in the front. I think of it as 8 groups of 5, then YA YU YO, WA WO N.