Hᴏᴡ Tᴏ "Aᴄᴄɪᴇɴᴅᴛʟʏ" Fᴀʟʟ Fᴏʀ Yᴏᴜʀ Bᴏʏғʀɪᴇɴᴅ's Bʀᴏᴛʜᴇʀ «ᵃ ᵒˢᵃˢᵘⁿᵃ ᵒᶠᶠⁱᶜᵉ ᵃᵘ»

Suna Rintaro has been engaged to Miya Ayurē for two years and they have been dating for five years, Ayurē is just a wolf in sheeps clothing but Rintaro is blinded by his love until he gets a call from his elder brother Rintora asking if he is allowed to marry his finace, Ofcourse at first Rintaro lies but when he asks his elder brother why he snaps and says that he broke the engagement with the said male.
Not knowing what to do after the phone call he cries in his best friend's arms at the Miya mansion as the second youngest Miya walks in with suitcase, Rintaro ofcourse only knows of the second Miya he's never officially met him but he does know that the second Miya is the next heir to the family business and decides to flirt with him but as a counter attack the second youngest Miya ends up asking Rintaro to marry him, how does Rintaro respond?