Suizei Tennō is the son of Jimnu. Suizei became the emperor of Japan in 581 BC.
There is actually no official source of Suizei. So, according to most historians, Suizei is a legendary character. However, because of the existence of a monument to Suizei in Japan, it is accepted by some historians that Suizei is a real one. And if Suizei actually exists, it is thought to be the son of Jimnu.
And according to historians Suizei died in 549 BC.