I usually use Eki-net which offer up-to 35% discount ticket.

This time I was going to take one ticket on 12/31 From saitama to Niigata,
but this period is called “kisei-rasshu” which means many people return to their home.

Today,I got an e-mail which said that I could not get ticket.
So, I searched another train which departs late afternoon.

Finally, I could get a ticket for 15% discount price!