For openSUSE Tumbleweed run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:ykoba:m17n/openSUSE_Tumbleweed/home:ykoba:m17n.repo
zypper refresh
zypper install opencc
For 15.5 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:ykoba:m17n/15.5/home:ykoba:m17n.repo
zypper refresh
zypper install opencc
For 15.4 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:ykoba:m17n/15.4/home:ykoba:m17n.repo
zypper refresh
zypper install opencc