What Does It Mean That Tregear and I Are Partners?

Plot direction Taiga before meeting Yuuki: With Earthlings? There is no need for any bond with that weak species. Taiga after meeting Yuuki: Yuuki, you are indeed the best partner! The huge 'bat' hidden in the cave; the inexplicable appearance of the island; the lonely ghost ship floating on the sea and the singing mermaid in the painting... During the adventure, the bond with Yuyuki continued to deepen, but... Who is this man in strange clothes with blue highlights?