"Why should it matter how old you are if you want to start something new?" 

The strongest guy around, who also happens to be middle-aged, strives to be an adventurer! Everyone seems to think you should pursue your dreams while you're still young, but there's one man who just can't give up. In a world where most people who become adventurers do so in their teens, a guild employee in his thirties, Rick Gladiator, seeks to become an adventurer instead. After receiving unimaginably brutal training from the legendary party renowned as the strongest on the continent, Orichalcum Fist, he ends up with combat abilities worthy of S-rank status despite starting out as an F-rank rookie! 
(Source: Crunchyroll)

Episode 1 - Starting 12 Years Late

Episode 2 - Number 4242's E-rank Promotion Exam

Episode 3 - A Super First-Rate Elite vs an F-Rank Ossan

Episode 4 - The Ossan Becomes an Adventurer

Episode 5 - Ossan, Trained to Death by the Most Powerful Party

Episode 6 - The King of Fists Elimination Tournament

Episode 7 - Ossan, the Fastest Preliminaries Qualifier in History

Episode 8 - Scales of the Heart

Episode 9 - The Perfect Prodigy, Born with Absolutely Everything

Episode 10 - The Strongest Pugilist in History

Episode 11 - Fistfight on Equal Ground

Episode 12 - Quarter Thumbs-Up

Yumeta Company

MediaNet

Nippon Columbia

Hobby Japan

Mainichi Broadcasting System

Asmik Ace

KLOCKWORX

Bit Grooove Promotion

AQUA ARIS

The Ossan Newbie Adventurer, Trained to Death by the Most Powerful Party, Became Invincible