Saioshi No Gikei Wo Mederu Tame, Nagaiki Shimasu! (b&arche) [Light Novel]

[Machine Translation] Alba finds himself reborn as the son of a poor nobleman. He is unable to use magic due to a disease, and his life is doomed to be short. There, he meets Orsis, who was his "most favorite" in his previous life. He is now the brother-in-law of the cause of the loss of the smile of his "most favorite"? Alba realizes the shocking truth and decides to cure her illness and become friends with Orsis in order to protect her beloved smile and to continue loving her brother-in-law. He lectures his father-in-law, who has a hard time with Orcis, charges into the forest where demons live in search of medicinal herbs to cure his illness, and praises his brother, who has low self-esteem.... His dedicated efforts and love are turning his destiny around...? A warm and heartwarming otherworldly reincarnation fantasy in which a reincarnated beloved son does his best to twist fate!

気が付くと、貧乏貴族の息子に転生していたアルバ。病のせいで魔法も使えず短命な運命を背負った彼は、公爵家に引き取られることに。そこで出会ったのは、前世で「最推し」だったオルシス。「ま、まさか俺って、最推しが笑顔をなくす原因の義弟!?」衝撃の事実に気が付いたアルバは、最愛の笑顔を守るため、そして義兄を愛で続けるため自分の病を治し、オルシスと仲良くなることを決意する。オルシスにはツンだった義父をお説教したり、自分の病を治す薬草探しに、魔物の居る森へ突撃したり、自己評価の低い兄を褒めまくったり...そんなひたむきな彼の努力と愛が、どんどん運命を好転させていき―?転生愛され令息が全力で運命を捻じ曲げるあったかほのぼの異世界転生ファンタジー!