Min-Min’s brother A-Di seems like the comic relief in “Yi Yi,” a character who doesn’t fully belong in the family, and arguably doesn’t fully belong in the film as well. I don’t mean that as a criticism, he’s more like a dried red pepper floating in the dish that you sometimes accidentally eat.

A-hi feels to me like a leftover character from Edward Yang’s previous film, the comedy “Mahjong.” He’s someone who wants desperately to be perceived as a winner — someone who’s rich and popular, with an attractive wife, a baby on the way, even an ex girlfriend who isn’t over him. But this sequence of scenes reveals how all of that is a lie.

It begins with A-Di getting off the elevator on the Jians’ floor. He’s dressed only in a t-shirt and boxer shorts — no shoes either. He hears people coming, so he quickly hides behind a corner. The guru is just coming out of the apartment with Min-Min’s coworker and NJ seeing them off. After they get on the elevator, NJ looks over in A-hi’s direction as if he thinks someone is there, but he turns back towards his apartment.

The next shot shows A-Di showing up at the doorstep of his ex-girlfriend Yun-Yun. He asks for $300 to pay the cabdriver, who he says is waiting, but we never see her give him cash or him leave to pay the driver … and none of it really makes sense, because if he stopped by purely to get the money for the cab, where was he going next? But Yun-Yun sees through it and declares “you’d go crazy without me.” It’s a funny line considering that she’s the one who crashed his wedding reception.

So why is he there in his underwear late in the evening? We get some details, but they don’t fully add up. His wife “went crazy” and threw him out. Why? We’re not told … but he doesn’t have any money, so maybe that’s part of it. Even though he showed up at NJ’s he couldn’t go in because he still owes him money and feels ashamed.

Yun-Yun asks what happened to the 9 million (which is about $300,000) that she gave him to pay his debt? A-Di tells her that he gave it to someone named Piggy to invest for him. Yun-Yun tells him that Piggy is on the run in China somewhere, but A-hi disputes this.

But before I go on, I have to stop and explain the bizarre atmosphere of this scene. A-hi is in bed with Yun-Yun, not wearing a shirt. She is in a nightgown and appears to be getting ready to go to sleep … so I guess we shouldn’t read too much into this … except the audio from the TV A-Di is watch certainly sounds to me like porn. And I have to wonder at this point — could A-Di have possibly done something to get thrown out of his house that is worse than what he’s doing right now?

But Yang has no interest in solving these comic riddles for us, he wants us to just soak them in and keep asking questions, it’s funnier that way. So A-Di says that he knows Piggy hasn’t taken off with his money, he just won some money off him playing mahjong the week before. He gets Yun-Yun to agree to go with him the next morning to see Piggy face to face.

When they arrive the next morning, the place is completely cleared out, other than stray items left behind. He whines that he’s broke again … she asks him why he trusted someone like Piggy … it all ends with him throwing a fit over his bad fortune.

The interesting thing about A-Di is that he is a loser, in a sense — chronically broke and in debt, apparently talentless, overweight, someone who has terrible taste in friends. And yet, he’s also extraordinarily lucky — women are still somehow interested in him and can’t let go … and he’s also about to become a father. It’s the tension between his good and bad luck that keeps him in the story.