Fervent Kiss

Both dramas involve the ML being asked to pose as his twin brother. In Fervent Kiss, its by his uncle, and the FL takes time to figure it out, whereas in Be Your Knight, the FL drags the ML into the story and the rest of their family, mainly their aunt, figures it out over time.
The rest of the dramas have different vibes, one in modern setting, the other in a more dangerous republican era setting.

Both are mini dramas in which the ML poses as his identical twin, as the FL who he was in love with tries to figure out his identity and secrets.

Both are mini dramas in which the ML swaps identities with his identical twin brother.
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