Bob is in love with Alice. Alice is on friendly or at least amiable terms with him, but she doesn't really seem to feel the same way about him, and most of the time Alice doesn't know how Bob feels at all.
Then one of two things happens:
1: Bob gets an idea of something that could improve his reputation, and he has an Imagine Spot
about how that would play out. This inevitably results in a scene of Alice suddenly way more impressed with Bob than the accomplishment really would indicate, swooning over him and basically putting Bob in the perfect position to ask her out or confess his feelings.
2: Bob does something bad, and is having a nightmarish Imagine Spot
about everyone's reactions, and this will inevitably end with Alice suddenly hating his guts and leaving him in the dust with an extremely overblown Ship Sinking
that the incident doesn't remotely merit.
In short, Bob comes across as either being a Horrible Judge of Character
, or else someone who chronically overestimates just how much his actions will change Alice's opinion of him, positively or negatively, in a way that is nearly always Played for Laughs
(I'm open to alternate trope names, but the other names I came up with were pretty ridiculously verbose, so I thought I'd use this one, named after one of the biggest examples in Western Animation, as a placeholder)
- The titular main character from the series Doug regularly has fantasies like this about his crush, Patti Mayonnaise. These fantasies almost always end with Patti saying "Oh, Doug!", followed by some relevant comment about him, and either loving or hating him for utterly ridiculous and/or OOC reasons.
- This also happens regularly in To Love-Ru. Yuuki Rito occasionally has these, mostly the type-2 day terrors, about how his crush, Sairenji Haruna, will suddenly hate him for utterly petty reasons. These get so bad that Nightmare!Haruna comes off as an Ice Queen Alpha Bitch. Run also has a tendency to have type-1 fantasies about Rito as well.