Seven:
Amu
Ran
Miki
Su
Dia
Yoru
Aruto Tsukiyomi (Ikuto's father)
Seas:
Aruto Tsukiyomi, Ikuto's father, was lost overseas.
Treasure:
Amu Hinamori is the treasure Ikuto has been searching for.
You would mostly get touched if you were an Amuto fan like me. But even if you ship Tadamu or other Amu/Ikuto related couples, you could still get touched by Seven Seas Treasure's meaning.