is bleach episode 188 filler?

Ichigo tells Rukia Kuchiki to take care of Rurichiyo Kasumiōji, which she agrees to do before running to her. Amagai asks if Ichigo, whom he claims is a very curious person, won't pull out of something that he isn't involved in.

Hearing this, the Substitute Shinigami enters Bankai and lunges forth to attack Amagai; though the Shinigami captain tries to counter by attacking Ichigo, his attacks are both deflected and dodged. Amagai starts using his Bakkōtō against Ichigo and reminds him that it seals a Shinigami's power, as well as their Zanpakutō's; he adds that Ichigo doesn't stand a chance against him, and that he should give up on trying to save Rurichiyo.