Verrrry verrry chocolaty!!

That’s exactly how I‘d describe this day. I woke up to find a Cadbury’s Dairy Milk chocolate (Family pack) waiting for me in the freezer. My cousin had kept it there after getting back home from work. It was my prize for completing the crossword in MidDay!
“There’s no way you can complete it”, he said
“And what if I do? What do I get?”,I ventured.
“You name it, you got it!”
“How about a bar of chocolate ?”
“Fine! Family pack!!”
“Done!”
For the next half hour, I found myself squinting at the crossword, reading the clues and filling in the words I knew. It was half complete by now. I managed to guess a few words correctly. I finally found myself wrestling with the clues to the last three words. Just three words away from my chocolate…I could imagine sinking my teeth into it, the chocolaty crust melting in my mouth. Pop!! went the picture when I realized that there was no way I could know the answer to these clues.
My chocolate cravings grew stronger by the minute and so did the feeling that I’d never be able to complete the crossword. There was just one missing blank in all three words and all three words were three-letter words and the three clues to the three three-letter words were keeping me away from three bars of chocolate which would be waiting to be devoured by me in the freezer the next day (I didn’t know that then, did I?) AND all the three missing letters in the three words were vowels!
The three clues were:
1) Colourful form of common carp K_I
2) A marine mammal, shark, whale et al _RL
3)”The” in German D_R
It’s obvious that the missing letter is a vowel in the second and third word. “How do you know that the missing letter in the first word is a vowel?”, you may want to know.. That’s because the words appeared in the crossword like this

K_I
R
L
There was only one intelligent way left to complete this crossword. The very next moment I found myself making these noises aloud
“KAI!” “ARL!” No.. Can’t be
“KEI!” “ERL!” Ummm…no!
“KII!” “IRL!” No way!
“KOI!” “ORL!” Maybe!
“KUI!” “URL!” Maybe!

It’s either ‘O’ or ‘U’.. after a lot of thinking, I resorted to
“IN PIN SAFETY PIN, IN PIN OUT! OUT GOES THE SAFETY PIN, IN PIN OUT!!”
I was left with ‘O’. Wow! O, the symbol denoting eternity! “May I be blessed with the joy of experiencing the wonderful taste of chocolates melting in my mouth for the rest of my eternal life”, I thought as I drew a big circle between K and I.
Now everything depended on the last word D_R ->”The” in German.. Let’s try using the word with different vowels in a sentence, I thought..
“Dur Mein Kampf!” No…can’t be
“Dor Mein Kampf!” Nnnnah!
“Dir Mein Kampf!” Nnnnno!
“Der Mein Kampf!” Maybe..
“Dar Mein Kampf!” Maybe..Maybe not!
It had to be either E or A. Let’s see.. what would Hitler say??
“Have you read dar book ‘Mein Kampf’?”
“Have you read der book ‘Mein Kampf’?”

“Eeeeeeeeesequallto (is equal to) my chocolate!”, I said as I wrote a big ‘E’ between D and R. I proudly thrust the newspaper into my cousin’s hands.

“You do seem to know a lot of words!”
“What did you think?!”
“Wow! I didn’t know a couple of them myself!”
“You may leave the chocolates in the freezer…”