The mask looks familiar...
Isshin shows up in the human world and meets up with the two shinigamis on patrol. The previous shinigamis met their end when it rained, so Isshin tells the patrol that they are dismissed if it starts raining.
At the same time, Masaki is having dinner at the Ishida's mansion with Ryuken Ishida's mother. Masaki is the last of the Kurosaki Quincies and thus the Ishidas have taken her in and the not-so-secret plan is to have Masaki marry Ryuken. Ryuken's father is not around, and his mother rather stressed out about Masaki's lack of progress in Quincy training. Masaki acts all nice and cheerful, but Ryuken can tell that she knows what's going. Ryuken himself is concerned about the situation and he wants Masaki to have a positive outlook on the future of the Quincy.
It's raining outside. Isshin tries to draw in the enemy by releasing his reiatsu. The patrolling shinigamis watch from nearby but they are cut down by something. Isshin notices and jumps in to investigate, and he spots a humanoid hollow/Vizard creature with blades for arms.
So Masaki was in an arranged marriage with Uryu Ishida's dad. That would explain why Isshin and Ryuken knows each other, since Isshin would eventually become Masaki's husband. I guess Ryuken never bothered to tell Uryuu about this bit of family history, and neither did Isshin or Masaki tell their own children.
Meanwhile, Isshin confronts the assailant behind the shinigami deaths, and it's probably something from Aizen's hollowfication experiments. The creature's head has some resemblance to Ichigo's hollow-fied form, and that's likely not a coincidence. I'm looking forward to the next bit of the Kurosaki family history, but unfortunately Bleach is off next week.