I played it too. Headache man. Although the concept is simple but you still need to play it like an actualy guitar!

The concept is pretty easy actually, the jap part is only on the songs and hwo to strum a guitar and what not. Which is a no brainer. But there might be hidden tricks or more information about playing the game in jap. Shrug, in a nutshell its pretty easy to play this game but very hard to master it.

Yeah it is enjoyable, the whole system is a no brainer when you actually play it. Strumming the guitar, getting the right chord, they all feels, right in a sense.

Jam session is the english version while this is the japanese version.

Only difference will be the included songs and lyrics i suppose.