Who is the father?

Ricki marries Takejirou 03/29/1887, but he dies 02/07/1890.
She marries his brother Masakichi 04/04/1890, still looking for a death date.
Grandpa is born (koseki date) 04/26/1887.
Every nesei will argue, but produce a real document other than the koseki and you win....