reproduced. Lastly, we discuss parity-flavor symmetry breaking for 2-flavor cases. These results suggest that we can take a chiral limit by tuning a mass parameter in lattice QCD with staggered-Wilson fermions as with the Wilson fermion.

This paper is organized as follows. In Sec. \[sec:SWF\], we review staggered flavored-mass terms and two types of staggered-Wilson fermions. In Sec. \[sec:Sym\], we study discrete symmetries of staggered-Wilson fermions. In Sec. \[sec:HPE\], we study hopping parameter expansion in lattice QCD with these fermions. In Sec. \[sec:EPA\], we investigate Aoki phase structure by effective potential analysis. In Sec. \[sec:Tf\], we discuss parity-flavor symmetry breaking in two-flavor cases. In Sec. \[sec:SD\], we devote ourselves to a summary and discussion.

Staggered-Wilson fermions {#sec:SWF}
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Before looking into staggered-Wilson fermions, we review the Wilson fermion and its relatives. The Wilson term splits 16 species of naive fermions into 5 branches with 1, 4, 6, 4 and 1 fermions. We call this kind of species-splitting terms “flavored-mass terms". As shown in [@CKM1], there are 4 types of flavored-mass terms for naive fermion which satisfy $\gamma_{5}$ hermiticity. ($\gamma_{5}$ in the naive fermion is flavored such as $\gamma_{5}\otimes(\tau_{3}\otimes\tau_{3}\otimes\tau_{3}\otimes\tau_{3})$ in the spin-flavor representation.) All these terms with proper mass shifts lead 