Its the same as Samba de Amigo (original) -the main menu top down goes: arcade, original, challenge. Internet and options are near the foot of the list.. Do the challenge games to unlock new tunes etc. Options will help you get your height correct for the maracas.
Go to liksang.com to buy maracas - and search google for screenshots to map out the english menus vs the Jp ones. I'm 100% sure you can find an english manual on the web somewhere.. if you search.