About
She was 22 years old when Tatsuya confessed to her. Now 37, her breasts have grown even larger since then. attracting unwanted stares from men. Because of that, she has wasted her marriageable period. For 15 years, she remembered and clung on to that promise, letting her love grow stronger and stronger, until it drove her insane. Deep down, she knows where his true love lies, but refuses to acknowledge it no matter what (as doing so would mean she's been living a lie). Instead, she opts to fulfill that promise by force using sleeping drugs to sedate him. and taking advantage of her sexy body to ensnare, and force a rushed consent out of him, thus making the marriage practically official.
(Source: the manga's character introduction)