A Middle-Aged Farmer in the Countryside was the Strongest: The World Found Out His True Strength After He Exterminated the Highest Ranked DragonSaikyou wa Inaka Nouka no Ossan deshita ~Saikou Rank no Dragon o Kujo Shita Kekka, Jitsuryoku ga Sekai ni Baremashita~, 最強は田舎農家のおっさんでした～最高ランクのドラゴンを駆除した結果、実力が世界にバレました～, The Strongest was a Country Farmer Old Man: As a Result of Exterminating the Highest Rank Dragon, His Ability was Revealed to the World