*There is also wi and we but it has been obsoleted.
beside those main character, there are also other 5 sounds that can be made by adding affix either a two tiny lines similar to a double quotation mark called dakuten （濁点） or a tiny circle called handakuten （半濁点） to the character. it's called, the muddied sound. Muddied sound affixes can only be applied to consonant /k/, /s/, /t/, and /h/.
/k/ with dakuten make the sound /g/, /s/ with dakuten makes /z/, /t/ with dakuten makes /d/, and h with dakuten makes /b/ while if it is with handakuten makes /p/.
Notice that 「ぢ」 sounds essentially identical to 「じ」 and both are pronounced as / ji /, while 「づ」 is pronounced like / dzu /
Last, there are small /ya/, /yu/, /yo/, and /tsu/. Small /ya/, /yu/, /yo/ is used to add their sound to a character like in nya = 「にゃ」 while small /tsu/ used to carry the consonant sound from the next character like in kappa = 「かっぱ」.
Notice that all character that can be combined with small /ya/, /yu/, and /yo/ are from the vocal /i/
Okay. That's all for Hiragana. Of course you won't remember them just by staring at them so here's your homework
Then let's move on to the next class