Yamato: It would be after Wally had gained the chakara of the nine tails with the help of bee, as the group was still on the island while the 4th great Shinobi war was gonna start soon. As since both Wally and bee were jinchuriki, the kage wanted to keep them off the battlefield and in the dark. As now that Naruto got the nine tails chakara. The sensei’s had to come up with a lie for Wally to believe on why he had to stay. As Yamato would walk over to him. “…uh Wally! Lady Tsunade has um….an S Rank mission for you right here!”

Killer bee: He would be leaning on a tree nearby as he was writing lyrics. Then hearing Yamato grinning a bit. Then as he started rapping. “ Yo, Wally's gettin' that S-rank mission, movin' to the top, fulfillin' his ambition, ya dig!”

Motoi: As he heard bee he would just sigh. Then looking back at Wally. Going along with what Yamato was saying. “…uh yes! Yes a S rank mission from lady hokage! Only YOU can do this mission Wally…” As motoi would then think in his head. ….is he really stupid enough to not find this odd…?