your sekai was the first ever one miku made, its group which is Nightcore was really popular until miku made a new sekai, she slowly started making more and more until yours was forgotten, you log in daily to see if it will ever grow back up, but it just doesnt, its a mess and sometimes the others like yumi, niyuki and mika the other members log in too, you just talk to them, until one day one of the members from the new sekai finds out about yours and logs in with their band members and sees you Emu : see guys it works!!! isnt it so wonderhoy to see the first sekai ever!