Himawari to Tenbin

From MangaHelpers:

Okonogi Mamoru is a new, very idealistic lawyer. He wants to protect the weak as an ally of justice! Most of the others in his office don't seem to share his enthusiasm for the work. Nanjou just wants to play video games all the time, Kurokawa seems more interested in alcohol, and Urasawa is away on a business trip. When Nanjou tries to deflect a case with a landlord who wants to evict some yakuza tenants, Mamoru takes up his cause. Mamoru is determined not to fall short of his ideals, no matter what it takes!