Gunjin no Niizuma: Reiri na Gunjin to Itetsuita Reijou

Hinako Fujinami, a countess's daughter, became known as the "Frozen Young Lady" after being mistreated by her stepmother and half-sister, suppressing her emotions. Her uncle arranges a marriage between her and Colonel Yosuke Umezono of the Imperial Japanese Army, and she accepts the proposal to escape her home. However, when Yosuke proposes marriage, Hinako's heart begins to waver... A Taisho-era romantic love story in which she learns the warmth of love through marriage!

(Source: Manga Box, translated)