Self made. Too much "Tekagen" for the weaker and Black won. "Tekagen" means "Showing your inferior move to let the weak players feel at ease".
It's one of Japanese culture. Apologies for the long description.
(;SZ[5]AB[cc]AW[bd]AB[cd]AW[ce]AB[de]AW[be]AB[dd]AW[bc]AB[db]AW[cb]AB[ca]AW[bb]AB[da]AW[ba]LB[cc:1]LB[bd:2]LB[cd:3]LB[ce:4]LB[de:5]LB[be:6]LB[dd:7]LB[bc:8]LB[db:9]LB[cb:10]LB[ca:11]LB[bb:12]LB[da:13]LB[ba:14]AW[dc]LB[dc:16]C[Black 15 passed. What should Black do after the Tekagen to make his strength just like the close level to White ? (NO COMI)FORCE]AP[goproblems]
(;B[eb]C[FORCE]
(;W[ec]C[FORCE]
(;B[ed]C[Well done;)RIGHT])
(;B[ea]C[Nope.])
(;B[ee]C[FORCE];W[ed]C[Nope.])
(;B[ae]C[FORCE];W[ea]C[Nope.])
(;B[ad]C[FORCE];W[ea]C[Nope.])
(;B[ac]C[FORCE];W[ea]C[Nope.])
(;B[ab]C[FORCE];W[ea]C[Nope.])
(;B[aa]C[FORCE];W[ea]C[Nope.]))
(;W[ed]C[FORCE]
(;B[ec]C[Well done;)RIGHT])
(;B[ea]C[Nope.])
(;B[ee]C[Nope.])
(;B[ae]C[FORCE];W[ee]C[Nope.])
(;B[ad]C[FORCE];W[ee]C[Nope.])
(;B[ac]C[FORCE];W[ee]C[Nope.])
(;B[ab]C[FORCE];W[ee]C[Nope.])
(;B[aa]C[FORCE];W[ee]C[Nope.])))
(;B[ec]C[Well done;)RIGHT])
(;B[ed]C[FORCE]
(;W[eb]C[FORCE]
(;B[ec]C[Well done;)RIGHT])
(;B[ea]C[Nope.])
(;B[ee]C[FORCE]
(;W[ec]C[Nope.])
(;W[ea]C[Nope.]))
(;B[ae]C[FORCE];W[ea]C[Nope.])
(;B[ad]C[FORCE];W[ea]C[Nope.])
(;B[ac]C[FORCE];W[ea]C[Nope.])
(;B[ab]C[FORCE];W[ea]C[Nope.])
(;B[aa]C[FORCE];W[ea]C[Nope.]))
(;W[ec]C[FORCE]
(;B[eb]C[Well done;)RIGHT])
(;B[ea]C[FORCE]
(;W[eb]C[Nope.])
(;W[ee]C[Nope.]))
(;B[ae]C[FORCE];W[ee]C[Nope.])
(;B[ad]C[FORCE];W[ee]C[Nope.])
(;B[ac]C[FORCE];W[ee]C[Nope.])
(;B[ab]C[FORCE];W[ee]C[Nope.])
(;B[aa]C[FORCE];W[ee]C[Nope.])))
(;B[ea]C[FORCE]
(;W[eb]C[Nope.])
(;W[ec]C[Nope.]))
(;B[ee]C[FORCE]
(;W[ed]C[Nope.])
(;W[ec]C[Nope.]))
(;B[ae]C[FORCE];W[ec]C[Nope.])
(;B[ad]C[FORCE];W[ec]C[Nope.])
(;B[ac]C[FORCE];W[ec]C[Nope.])
(;B[ab]C[FORCE];W[ec]C[Nope.])
(;B[aa]C[FORCE];W[ec]C[Nope.]))