友達はぼくをケンと呼ぶ。

friend; companion

topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis

I; me; you; manservant

indicates direct object of action; indicates subject of causative expression; indicates an area traversed; indicates time (period) over which action takes place; indicates point of departure or separation of action; indicates object of desire, like, hate, etc.

tendon

if; when; and; with; particle used for quoting (with speech, thoughts, etc.); quoting particle; promoted pawn; indicates question (sentence end)

to call out (to); to call; to invoke; to summon (a doctor, etc.); to invite; to designate; to name; to brand; to garner (support, etc.); to gather; to take as one's wife