I bought my underwear at Seiyu for 700 yen ($6.73 €4.93). At first I went to Uniqlo which is a common outfit store. But there were many people in stores on last Sunday and Monday (Monday was Emperor's birthday = holiday), and there was a long waiting queue at the casher in Uniqlo. I hate to wait in a queue. I gave up to buy the wear at Uniqlo, then went to Seiyu. Seiyu was also crowded, but fortunately a queue was not so long. I bought it at Seiyu.