Episode 9 was a departure, featuring Ayako visiting Mamoru's home for dinner, with a lot of time between Ayako and Mamoru's sister, Itsumi. That this episode was so enjoyable was because of the two
seiyuus involved:
Takahashi Mikako as Ayako and
Shimizu Ai as Itsumi. Comedy + serious communication = win.
As I said in the
Gift~Eternal Rainbow~ thread, Ai seems to be growing professionally in the past couple of years: from Mikoto in
Mai-HiME, to Mitsuki in
He is My Master, to Sayaka in
Okusama wa Mahou Shoujo, to Tamao in
Strawberry Panic, and Riko in
Gift. Her career started in 2002 with a role in
Asagiri no Miko, but she first stood out for me as Karen in
Onegai Twins, with a great version of the tiny, drippy voice. She has developed a lot since then. She remains a favorite subject for photo sessions like
this one, from which the following clickable thumbnail comes. EDIT: I've added a little pic of Takahashi Mikako (Ayako) for good measure:
Mikako is 26, Ai is 25.