Oshi no Tsuma ni Tensei Shiteshimattanodesuga Okazari no Tsuma Dattanode Otakatsu wo Keizoku Shitaito Omoimasu

Lady Philine, the daughter of a poor baron, is in a loveless political marriage with Lord Volkhardt, the next marquis and royal magician. Being treated as a "trophy wife" by her callous husband, who's known as the "Ice Wizard," wears her out so much that, one day, she collapses... and all the memories from her past life come flooding back! In that life, she was a rabid fan of Volkhardt, a character from her favorite mobile game. Upon realizing that she is now in the game world, she decides to give up on receiving his love as a wife, and instead becomes determined to cheer him on with all her might as his fan. Converting their servants and pet dog into Volkhardt fans as well, she pours her body and soul into her fave, and starts making her own Volkhardt merchandise. Could doing all this bring about a change in her famously cold-hearted fave...?