《偉大的遺產》描寫的是三流流氓繼承了母親的幼兒園，在幼兒園遇見了孤兒出身的女教師后，墮入愛河的浪漫愛情喜劇。劇中金載沅扮演的是沒有夢想、沒有明天、過著毫無意義人生的“黑社會流氓”姜賢世，守護著繼承的“偉大的遺產”－幼兒園。韓智敏扮演的是沒有經驗的、雖然總是犯下錯誤但絕不討厭的幼兒園教師劉美蘭。她從小失去父母，在這個世上沒有依靠，但她身邊確有著很多可愛的幼兒園孩子們。本劇講述了原本是流氓的姜賢世當上幼兒園教師，繼承了幼兒園這個“偉大的遺產”的故事，一針見血的指出最近的幼兒教育忽視人性教育而更重視知識的傾向，希望等夠引起大家的思考，真正的教育是什麼？我們應該把什麼交給孩子們？通過姜賢世這個人物，展示了另一種教育的可能性。金載沅在劇中飾演一個渾渾噩噩過著日子的流氓，後來成了幼兒園老師。他曾出演《美好生活》、《北京，我的愛》和 《嫂子 19》等片。老是把事情弄糟的幼兒園教師俞未來一角由《復活》中的女主角韓智敏扮演。未來的前男朋友時煥，野心勃勃，想要奪走幼兒園，插在兩人中間。條件出眾的時煥由在《黃金蘋果》中飾演京九的金知鄖扮演。 好久沒在電視屏幕上亮相的李美淑扮演幼兒園的園監高雅娜。她和女教師劉美蘭以及曾是流氓的輔助教師姜賢世齊心協力保護幼兒園。本劇將著刻劃他們一起對付幼兒園虎視眈眈的會長和想賣掉幼兒園賺到好處的幫派頭子的找搗亂等內容，為本片增加趣味性。

Through its main character, former gangster and currently novice kindergarten teacher Kang Hyun-se, this drama criticizes the negative aspects of early child education, which prioritizes knowledge over character, and show what children really need. It opens the possibility of alternative education by portraying how Hyun-se transforms from a hopeless gangster into a warm-hearted kindergarten teacher played by Kim Jae-won. The role of his colleague, Yoo Mi-rae, who keeps making mistakes, is played by Han Ji-min. Mi-rae's ex-boyfriend, the ambitions Shi-wan, attempts to take over the kindergarten and hampers the two people from loving each other. Actress Lee Mi-sook portrays Ko Ah-ra, the director of the kindergarten who has her own philosophy about education and does her best to protect the kindergarten. She even stands up against powerful people who want to destroy the kindergarten to gain profits.