i guess the meeting between the mangaka and the editor went like this :
- mangaka : here is the plot for this chapter : the parents of a boy were "gone" , so he invites his girl-friend to his house . then she goes buying new panties . when they are in his bed-room , he takes off his clothes and asks her to take off her clothes too .....
- editor : great . dont tell me the plot anymore , just draw this chapter quickly .
( later )
- editor : yo , why are there bloods and gores in this romance chapter ?
- mangaka : you got trolled , lol .
page 5 : she is so nervous , she is sitting in seiza style on the sofa .
page 8 : what i truly cherish is your heart . can i see your bloody heart now ?
page 18 : later , they use that bird for the experiment . and i guess everyone can distinguish the twins more easily now , unlike page 10 in chapter 1 .
page 22 : look closely at the family tree and you will see :
2nd generation : one person 's spouse will re-marry another person .
3rd generation : 2 persons wont get married and stay as virgins . 1 person will adopt a children .
page 23 : the mangaka 's names , hiyodori and uguisu , are 2 species of birds or something . on her shirt , there is also a bird .
https://en.wiktionary.org/wiki/%E3%81%B2%E3%82%88%E3%81%A9%E3%82%8A .
https://en.wiktionary.org/wiki/%E3%81%86%E3%81%90%E3%81%84%E3%81%99 .
page 24 :
- twin chapter 1 : 2011 .
- twin chapter 2 : 2013 .
- burial valentine : 20 / 3 / 2012 , 1 week after White Day 14 / 3 .