Five-body resonances in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>He</mml:mi><mml:mprescripts /><mml:none /><mml:mn>8</mml:mn></mml:mmultiscripts></mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi mathvariant="normal">C</mml:mi><mml:mprescripts /><mml:none /><mml:mn>8</mml:mn></mml:mmultiscripts></mml:math> using the complex scaling method

We study many-body resonances in the neuron-rich $^8$He and mirror proton-rich $^8$C using $^4$He+$N$+$N$+$N$+$N$ five-body model with isospin $T=2$ system. Resonances are described complex energy eigenvalues as Gamow states scaling method. In $^8$He, we obtain five states, which four resonances, all resonances.We discuss isospin-symmetry breaking dynamically induced by Coulomb interaction spectra decay widths of two nuclei. predict resonance energies for future experiments. also investigate configurations valence nucleons above $^4$He nuclei $jj$ coupling scheme dominantly have $p$-shell configurations. From configuration mixing, give similar results, indicates good symmetry