If I play Kamado but only have one other card in my hand to choose from, do I get to draw 4 cards even though I don't discard any from my hand?
Yes, you can. Since you were able to choose a card in your hand, you get to draw 4 cards.
Source: TPCi Rules Team (2022-07-07)

Relevant cards

Note: All applicable cards may not be listed below.
SWSH10_149
SWSH10_149