Grown-up Kusano is quite the looker.
Kusano is still asleep and wouldn't let go of Minato's shirt. Kusano dreams that she would turn into an adult to give her declaration to Minato. Kusano is woken up by Seo and his Sekireis' arrival. Other than staying over to freeload dinner, Seo has a letter for Minato and also wants to talk to Miya about something. Minato sees the letter is from his old landlord, but then opens it and discovers that it's written by Shigi Haruka whom along with his Sekirei Kuno had escaped the capital thanks to Minato's help. In the letter, Shigi tells that he and Kuno are doing okay. They couldn't communicate with Minato electronically, so they sent the letter through Shigi and Minato's old landlord. Shigi is concerned about what's happening now, and he is giving Minato his support.
After reading the letter, Minato sees Musubi in the yard. Musubi gives her declaration and repeats that she wants to be with Minato forever and ever. Minato also thanks Musubi for choosing him. The two get close but they discover that all the other Sekireis are peeking. Musubi states that she wants to be with everyone, and Minato declares that they'll win this competition to make sure it happens.
I thought Musubi might get an extra-long declaration since she's the first wife, but it's good that they are done. With the declarations out of the way, hopefully we'll actually get to the Fourth Stage in the next chapter or two. Seo has some serious matter to discuss with Miya, so that might take another chapter given how Sekirei can move at a glacial pace. Having Shigi write a letter back to Minato was a nice touch, and it's good to see that the escapees are still okay.