Ondorium (Kokei)

"Is he just not interested in me...?" Anna is the second princess of the kingdom and is also originally from another world where she was a simple office worker. Recently, one of her brothers got a girlfriend, so now she's more than a little impatient. She has a fiancé, Roberto, from an allied nation, who has promised to marry her soon but refuses to see her. She decides to take matters into her own hands and find out about his feelings herself. Although they meet at parties and soirées, she has no idea what he does in the day-to-day. She acquires a magic potion that allows her to transform into another person and infiltrates the castle where he lives disguised as a maid. A tale of isekai reincarnation, confinement, and sweet-yet-obsessive love.