The simple wagashi.
It is “mizu-yokan”, water-yokan. Yokan is the thick bean jam block. This is a lighter hot season version, that was often molded in bamboo stalks. It’s made of koshi-an (fine azuki bean paste, here sweetened with kuro mitsu), water and gelatine.
If you are vegetarian, you can replace the gelatine with agar-agar, but it won’t be melty.
This is a fancy version, with sticks of raw nashi pear.
Eating the mizu-yokan at twilight :