Kensen Hyoukyoku

Setsuka, the third son of the mighty and immensely powerful country of Jan, always spent his days taking fencing lessons from a beautiful young woman named Karen alongside two hostages from an enemy country: Suiran and his childhood friend Shiraha. Then one day, everyone in the country of Jan is gruesomely attacked and slaughtered by the enemy country! But then, Kokuyou, a rookie swordsman with remarkable technique, arrives spearheading a group of smugglers known as the Karanhyoukyoku! Thus begins the grand story of crossing the continent to deliver Setsuka, who has become "baggage" due to being the imperial prince of a now-dead country, to a place of safety!

(Source: Square Enix, translated)