As usual, I'll go for examples which should come in handy. Check the emphasized words. (The translations are not natural, but it's not the point here.)
Sample 1
Won't you come visit me in France?
フランスに来ませんか？待っていますよ！
Won't you come visit me in France?
フランスに来ませんか？待っていますよ！
Yes, I will go to France. We will go see the Arc de Triomphe.
いいえ、フランスに行きますよ。一緒に凱旋門を見に行きましょう。
Yes, I will go to France. We will go see the Arc de Triomphe.
はい、フランスに行きますよ。一緒に凱旋門を見に行きましょう。
Great. Mark came last summer already. 良かった。去年の夏はマークさんが来たよ。
Great. Mark came last summer already.
良かった。去年の夏はマークさんが来たよ。
Sample 2
Will you come/go to John's party tonight?
今晩、ジョンさんのパーティに行きますか？
Will you come/go to John's party tonight?
今晩、ジョンさんのパーティに行きますか？
No, I won't go to John's.
いいえ、行きません。
No, I won't go to John's.
いいえ、行きません。
Paul is not coming/going either.
ポールさんも行きません。
Paul is not coming/going either.
ポールさんも行きません。
Sample 3
Come here!
来てください!
Yes sir! I'm coming right away. はい、すぐ行きます。
Come here!
来てください!
Yes sir! I'm coming right away.
はい、すぐ行きます。
Summary Tarou
Tarou is at place A, Jun is at place B. Tarou calls motions towards A as "来る". Tarou calls motions away from A as "行く". Tarou calls motions towards Jun as "行く".
行く/来る is fromfrom-here/to-here relatively to the person who uses the verb now. (I suddenly have a doubt for a situation like "will you visit me at my new home when I moved to France". I think "来る" would still be good, because it's still about the narrator being reached.)
