万次郎はこの二国をお互いに親しくするために一役果たしました。

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

this (something or someone close to the speaker (including the speaker), or ideas expressed by the speaker)

two

country; state; region; national government; central government; home (i.e. hometown, home country); province (of Japan); land; earth

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.

mutual; reciprocal; each other

at (place, time); in; on; during; to (direction, state); toward; into; for (purpose); because of (reason); for; with; by; from; as (i.e. in the role of); per; in; for; a (e.g. "once a month"); and; in addition to; if; although

intimate; close

to do; to cause to become; to make (into); to turn (into); to serve as; to act as; to work as; to wear (clothes, a facial expression, etc.); to judge as being; to view as being; to think of as; to treat as; to use as; to decide on; to choose; to be sensed (of a smell, noise, etc.); to be (in a state, condition, etc.); to be worth; to cost; to pass (of time); to elapse; verbalizing suffix (applies to nouns noted in this dictionary with the part of speech "vs"); creates a humble verb (after a noun prefixed with "o" or "go"); to be just about to; to be just starting to; to try to; to attempt to

for; for the sake of; to one's advantage; in favor of; in favour of; on behalf of; because of; as a result of

role (which someone or something plays in a given situation); part; contribution (to a given situation)

to accomplish; to achieve; to carry out; to fulfill; to fulfil; to realize; to execute; to perform; to do; to do ... completely; to do ... entirely