One Fish, Two Fish, Half Fish, Marine Biologist.

A Fin.

Mitsuki chatted with Izuku the whole way there and told him different things about their culture. Izuku listened intently of course until they got to the dining hall where Masaru was. They had just passed through two large doors that were opened for them by guards and the brunette was waiting by the long table for them.

"Ah, Izuku, nice to see you made it here okay." He greeted as the three swam in and Mitsuki quieted down

Izuku smiled.
"Hello sir-" he started until he realized he could understand the man when he couldn't previously

"Wait, I can understand you." The green headed biologist stated rather than questioned

"Of course you can, you're a merman now." Masaru nodded as Mitsuki moved to float beside him

"Turning makes you understand the language?" Izuku tilted his head not noticing Katsuki was beside him

Mitsuki nodded.
"Pretty much. It was a shock when I changed too." She answered

"Wow." Izuku said amazed then grabbed Masaru's hand to shake it

"It's so nice to properly meet you!" He smiled

"You too." Masaru smiled in return at the other's enthusiasm

Katsuki interrupted them though as he swam towards the table filled with food.
"Alright let's eat. I'm starving." He announced

Mitsuki rolled her eyes, but she and her husband went to their seats. Masaru gave a little chuckle as they sat down. They were at one end of the table while Katsuki took his seat at the other then beckoned his boyfriend to sit next to him. It mirrored the older couple Izuku thought and he sort of likes the sound of that. Mitsuki interrupted his thoughts a little bit after they started eating.

"So you said your name is Midoriya izuku?" She asked as Katsuki thought not for long

"Yes ma'am." The newer merman nodded eating whatever boyfriend plated for him

Eating such exotic food was new for him since he usually sticks with ramen and katsudon. Sometimes he had udon, miso, natto, or tonkatsu but he mostly lived off instant ramen and his mother's katsudon. He'll have to get used to the different flavors and types of food.

Mitsuki nodded, pursing her lips for a moment before speaking again.
"Are you related to a Midoriya Inko?" She questioned

"Um, that's my mother." Izuku said almost worriedly as Katsuki looked from his mother to his table partner

Mitsuki's eyes went wide.
"Holy shit." She said

Masaru looked at his wife confused.
"Honey?" He said as Izuku glanced at Katsuki who shrugged

"I know your mother." Mitsuki pointed at the green headed merman

"What?" Izuku asked completely shocked

"She and I used to be friends back when I was still a land lover."

Izuku's eyes bulged out of his head. Inko mentioned and even showed him pictures of her 'missing childhood friend' saying how much she misses her and hopes she's still out there. His mother didn't talk about her often which is why Izuku didn't realize until now.

"Y- you're that Mitsuki?!" He asked

"Hah?" Katsuki looked at his boyfriend

Mitsuki frowned, confused.
"She talks about me?" She questioned

Izuku nodded frantically with excitement as he ignored Katsuki.
"Yes! She said you went missing and she misses you. I had no idea she was talking about you though." He gestured to the mermaid