简介：NaDu-su(LeeSeung-hyeon),whosportsthenicknameof"Yalkae"(meaning"cheeky,cockyperson"),hasbeenahighschoolsophomorefortwoyears.Hispartner-in-mischiefYong-ho(JinWoo-young),whosefatherrunsahospital,isalsorepeatinghisgrade.Together,theyplaypranksontheirfriendsandteachersandneglecttheirstudies,therebyearninganotoriousreputationas"problem"students.Oneday,Du-sugoestothehouseofateachernamedBaekSang-do(HahMyung-joong),whorentsaroomfromagrocerystoreowner,forafter-schoollessons.There,hefallsforIn-suk(KangJu-hee),whosemotherownsthegrocerystore.WhenaclassmatenamedHo-cheoltellsonhimtoMr.Baek,hedecidestogetHo-cheolback.Duringclass,hepaintsHo-cheol'sglassesredandyells,"Fire!"Ho-cheolendsupgettinghisglassesbroken,andDu-sugetssenttotheprincipal'soffice.WhenHo-cheolfailstoshowupatschoolafterthatday,Du-sugoestohishouse.HeshedstearsofremorsewhenhelearnsthatHo-cheol,whosefamilyistoopoortoaffordanewpairofglassesforhim,fellduringhismilkdeliveriesandinjuredhisleg.Du-sutakesonthedeliveriesinHo-cheol'sstead.HeeventakesnotesinclassforHo-cheol,andbeginstodevelopaninterestinstudy.Whilecontinuingtorunthemilkdeliveryrouteinsecret,hegetsintoacaraccidentandhurtshisarm.Du-su'sgooddeedscometolightbecauseoftheaccident,winninghimtheapprobationofhisfamilyandhisteachers.EvenIn-suk,whohadpretendedtoactcoldlytowardDu-sutomakehimcometohissenses,visitshimwithabouquetofflowersinherhand.…