I will be going Japan for 15 days in August.
Any bro/sis can advice on the best train ticket to purchase whether to buy individual trip or what kind of train ticket should I get?
Not yet finalize the trip but I will be in Osaka then will be travelling to Koyto, Hiroshima, Nara, Takayama, Tokyo..
it depends how many days u planning to stay in each place.
are ur air tickets open-jaw? i.e arrive osaka, depart from tokyo?
if so, u can consider planning it such that u can cover the expensive train rides all within a 7-day JR pass.
e.g.
arrive osaka, cover kyoto, osaka, nara in the first few days.
activate 7 day JR pass to travel to hiroshima
travel from hiroshima back to osaka and to takayama
travel from takayama to tokyo before JR ends
spend remaining days in tokyo
and as thwysg mentioned, it is going to be crowded. so do book ur accom early