Good-sounding boys all have Japanese names, as long as they know Japanese.

Shui Mu Zuodou

Hayato

1 to 4 is the easiest to read.

2. Water tree

Shui Mu Youdou

Juto

Yuuto, there's a long note here, not as smooth as the first one.

3. Kuroha

A black tree

January

Not bad, but kuro and Japanese (Ku Kuang) are similar in pronunciation, so it is difficult to name them.

4. Seven Seas

Yi Shu Nanamei

January

This is a little feminine. There are seven beauties and nanami who have the same pronunciation as Nanami. Personally, I feel a little "sissy".

To sum up, I think the first song is the most smooth and pleasant.