You need an embassy visa for Bangladesh if you have a Japanese passport
Visa options for Bangladesh (2)
Visa on arrival for a maximum of 15 days for Tourism
Travelers need a visa to visit Bangladesh for Tourism. Travelers can get a visa on arrival in Bangladesh at the port of entry, such as an international airport or border crossing.
Visitor visa
Travelers need a visa to visit Bangladesh for Business or Tourism. A paper or embassy visa is the only visa available for travelers visiting Bangladesh. The visa is typically a stamp or sticker added to the passport. Travelers must obtain this visa from a local embassy, consulate or visa center before traveling.