BTMU is more of a retirement bank and some of the people hired there(as in whole bank) have no relevant skills to speak of because they are direct hired by the HOD themselves.
They either pass time by chatting with other colleagues or go toilet do makeup. Was from the bank previously and although culture wise they are very strict and regimental, but work load wise can be quite slack. If you are looking for retirement, Japanese banks are best. If you are looking for career progression, Japanese banks are huge no.