You really want me to explain just how a sentai show with the Beatles would work? M'kay, here goes nothing...
Back in the day, the Beatles were really crime-fighters who used mecha to fight Communists and other threats to the Western World; the band was just a cover, of course, but at least it paid the bills nicely. When John Lennon got involved with Yoko Ono, the team began to fall apart; in order to weaken them further, Yoko arranged for John's assassination and poisoned George Harrison. It's now 2006, and Paul McCartney and Ringo Starr are the only two surviving members; they've been recalled into service by the UN Security Council to fight terrorists and rogue leaders. Along the way, they also try to avenge the deaths of John and George by trying to hunt down Yoko.