So far I ran 265 Full Marathons and 26 Ultra Marathons based on my rules I posted. Below table is Full Marathon list from 251st to 265th, and Ultra-Marathon list from 1st to 26th I ran.

My PR for 100 km Marathon is 7:53:46 in the Iwate Galaxy 100 km Challenge Marathon.
Kawanomichi Foot race Japan Crossing is one of the most terrible Marathon race in the world. Its total distance is ~520 km and time limit is 132 hours. The course is basically River Beds of Arakawa River and Chikumagawa/Shinanogawa River from Tokyo bay to Niigata through two mountains.