Ibyuma by'Ubwoko bwa Mortise na Tenon Concave-Convex ni itsinda ry'ibice by'ubwubatsi bikozwe mu giti, bigenewe abana bato. Iri tsinda rigizwe n'ibice 211 byakuwe mu miterere gakondo y'Abashinwa ya mortise na tenon, byoroshywe bikaba ubwoko 30 bw'imikoranire nk'umukono w'imisego y'inyoni w'incuke (square dovetail) n'uw'ishusho ya T. Ibice bya tenon bikozwe mu giti cy'umwijima cy'igiti cya walnut, naho ibice bya mortise bikozwe mu giti kimurika cya beech, bityo ibi bice byombi bikamenywa hakurikijwe ibara. Ibice byubatswe hakoreshejwe imashini y'ubwubatsi bw'ibiti, hanyuma bikarangizwa n'amaboko. Hariho urwego rutatu rw'ubukana bujyanye n'abana bafite kuva ku mezi 18 kugeza ku myaka irenga itandatu, uhereye ku guhuza imikoranire imwe kugeza ku kubaka ibishushanyo binini.
Izina ry'umushinga : Concave-Convex, Izina ryabashushanya : Sha Yang, Izina ry'abakiriya : Shanghai Art and Design Academy.
Igishushanyo cyiza nuwatsindiye igihembo cyumuringa mububatsi, kubaka no guhatanira imiterere. Ugomba rwose kubona ibihembo bya bronze byegukana ibishushanyo mbonera bya portfolio kugirango umenye ibindi byinshi bishya, bishya, byumwimerere kandi bihanga imyubakire, inyubako nuburyo bwo gukora.