The player's cell phone is used only when there's a random call in the game - if one of the married Mii couples have a baby, they need help calming the baby down, the baby grows up, they get a letter from a traveler, a traveler comes to visit, or when it's the player's birthday. It is yellow with a cyan screen.
"Hi!" (US)/"Hello?" (In UK)/"Could you come for a moment?" [JP] - A married couple has given birth or their child has grown up, or received a letter from a traveler.
"Excuse me..." - The parents need help calming down their child.
"Ahem..." - A traveler has come home, or it's the player's birthday. The player's look-alike will always call on the latter.
The Mii's phone
When the player gives a Mii a cell phone as a level-up gift, often they will take the phone out, dial it, and pace the room while using different phrases. They also use the phrases the player gifts them, their face changing to match each one. The phone is colored grey with a blue screen.
These are some of the things a Mii might say while on their phone in their apartment.
"Ha ha ha!" (Happy)
"What?! Really?" (Surprised)
"No, no, no."
"[Mii], seriously?" (Surprised)
"In that case, yes."
"So, do you think [Mii] likes [Food/Treasure]?"
"Well, what about [Food/Treasure]?"
"What do you think about [Food/Treasure]?"
"[Food/Treasure]? I don't know."
"Please don't tell [Mii], okay?"
"[Happy phrase]" (Happy)
"[Mad phrase]" (Angry)
"[Sad phrase]" (Sad)
"[Worried phrase]" (Sad)
The Mii talks on his cell phone.
The Mii with a sad face, while saying its sad and worried phrases on the phone.