Apparently, Komari’s brother actually exists. Sadly, she has totally forgotten about him.
After watching this episode, I let it settle in little bit and then suddenly realized something. Komari’s situation with her older brother is very similar to Sayuri Kurata’s situation in Kanon. After both of their brothers died, they have changed psychologically as a result. However, Komari’s reason of why she forgot about the sad memories with her brother is quite understandable. Maybe this has to do with her making a promise with him that cannot be fulfilled while his brother tells her that it’s just a dream so it wouldn’t impact her as much. This possibly explains why Kojirou doesn’t want Riki to have her remember the sad memories and also the picture book with the forgetful chickens. She will just become depressed again as a result. Unfortunately, she recalls her memories after watching shooting stars with Riki and taking him on a boat ride.
On the other hand, I also fail to see how Riki becoming Komari’s older brother replacement will solve the problem. Sure, she can forget the sad memories, but in reality, it does little to resolve the promise she made with him and the sad memories. While she may try to take him as her older brother, I think he will find some way to comfort her so she can look back at it positively rather than living in a lie.
Aside from that, there were a few comedic moments underneath the sadness. Besides Komari calling Kurugaya “Yui”, both of them aided in helping Rin say Komari’s name. It’s just funny how everyone has to resort to deception just to make her say it. It just shows that Rin has a long way before she can overcome her shyness for good.