History's Strongest Disciple Kenichi sales according to Oricon. Oricon only lists the top 50 best selling manga during a week. Sales are counted from Monday to Sunday. The number in brackets denotes the number of days a volume was on sale during its first week (i.e. if it was published on a Friday it will have only three days of sales that count towards this week's ranking.)There was no available data for volumes 1-28. Some volumes were available as regular version and special version that included extras like can badges, OVAs, postcards, etc.