A Sister's All You Need., Vol. 13 (light novel) by Yomi Hirasaka

Winter ends, spring arrives, and our protagonists take a new step forward. Harutoannounces a new series. Miyako joins Branch Hill Publishing to finallybecome aprofessional editor. Chihiro becomes the life of heruniversity's TRPG club. Finally, a100,000-character love letterinspires Itsuki to pour more energy into his novel andbecome a genuineprotagonist. A new everyday life dawns as the series enters the firsthalf ofits final chapter!
Binding: Paperback / softback