LOL that's true , there's always a kid in everyone & the fact that DAIGO's a talento , it doubles the fun as it's his job to make people laugh at him whenever he appears on variety shows :p
They performed at the Budokan for 3 straight years already but yeah the 1st time when they performed 2 years ago , it was very emotional for them , especially for DAIGO
The last min or so from that clip features them performing Hikari as the encore no. & they wore the same outfits they did for the promo of the single as well
They usually close off their setlists with Hikari but that particular performance of Hikari they did was really heartbreaking ;_;
I suppose alongside with GRAND FINALE , Hikari is a very significance song to them , especially since both songs were composed & written by DAIGO himself
I don't know if they plan to conquer Tokyo Dome next but they have accomplished a lot & worked their butt out for the past 4 years so anything's possible =D