So there old man 30-40 years transfered in other world as adventurer . But he got prisoned in first chap with a young girl.. First time he meet a young girl knight in empire in prison by some reason.. But there accident on castle then make that old man (mc's) and young girl able to run away .. Then she and he dropped in forest ... And last part i remember that old mand the girl start journey .. But unfortunately they faced a dragon ancient lvl 99999 .. And the young girl the last chap i read she fall in love with mc's

Tanaka The Wizard