Some names explanations and some places the characters go often to. All in alphabetical order. ^_-

Akindo: The "make and sell anything" club founded by Tsutomu, Yuusuke, and Jiro. All the members works to create things that then they sell at the flea market; "Akindo" means "merchant" or "shopkeeper."

Berry-chan: It's Akindo's mascotte and looks like a mix of Mikako and her Happy Berry logo.

The Blue Parrot: It's Tokumori's bar where Ruriko is used to go. There are some special appearings and cameo from Tenshi nanka ja nai.
As Yazawa-sensei states in one of her freetalks, the Blue Parrot is an existing bar in Okayama and its owner's name is Tokumori just like in the manga! XD

Futari no Fantasia: It's the manga written by Ruriko. It is a pure and virginal shoujo story, nothing to do with Mikako's life (as someone may suppose that Ruriko writes her manga taking the cue what happens to her daughter).

Happy Berry: It's Mikako's brand name: a small berry with wings.

Kira-kira Seijiin: It's Kisaraji's nickname and it means something like "sparkling alien". Kira-kira is the onomatopeic word for "to sparkle".

Afternoon mera-mera girl: It's Mikako's nickname, referring to her passion for the afternoon classes at Yazagaku. Mera mera is an onomatopeic word for burn.

Kuro: Mikako's cat; it's translation is "black".

Sally: It's the name Mikako gives to her scooter.

Shiro: Hirohiko's white cat. Its name means "white"