Marry Me!

Civil servant Sinn gets a huge surprise on his 29th birthday when he is chosen as the first subject of an experimental new law to marry someone he's never met. His marriage partner is Mari, a recluse who has yet to experience the small joys of life. Now the two must navigate their relationship as a married couple, all while proving -- or disproving -- that the law will benefit the greater good of society.
(Source: WEBTOONS)
Note: Webtoon version contains 134 chapters.