From MAL
This fanbook contains short manga as well as illustrations, an interview, and features about Natsume Isaku's working habits. There are a series short manga starring the characters from all of Natsume Isaku's mangas interacting with each other. Other mangaka also contribute short manga featuring Natsume Isaku's characters. 50 new pages have been drawn especially for this fanbook.

[From Nakama]

Since there is no back cover blurb here are the contents:

Natsume Isaku Special Illustrations
Let's go to the super bath-house! … 3
Amber Paradox - Masaya and Satoshi … 11
Amber Paradox - Tale of the Night … 18
Tight rope - A tale, half asleep and half awake … 27
Doushiyoumo Nai Keredo - Night of sake … 36
Doushiyoumo Nai Keredo - Let's go to my parents' house! … 41

Popularity poll results — publication … 53
Question for Natsume Isaku-sensei! … 64
Color Illustration Selection … 65

Guest Comics
SHIMIZU Yuki Sugar Code Yakuza Man … 97
YAMASHITA Tomoko Amber Paradox Onoe is definitely set to smash an important setting* … 101
AMAGAKURE Gido Doushiyoumo nai keredoYou're cute whatever you do … 105
AMAGAKURE Gido Ikasama Memory A promising future … 111
YAMADA Nichoume Heart no Kakurega Arm pillow … 113
YAMADA Nichoume Heart no Kakurega Rolling arm pillow … 115
YAMADA Nichoume Doushiyoumo nai keredo
A satisfactory arm pillow … 116
MONCHI Kaori Tight rope Sleeping on someone's lap … 117
Koshino Amber Paradox Paparazzi hotel … 122
— Guest Profile & Message … 124

Uncompiled Tankoubon Comic and Illustration — Re-compilation
Doushiyoumo nai keredo Flower Friday ④ … 126
Doushiyoumo nai keredo Before the morning sparrow disappears … 141
Doushiyoumo nai keredo Something very unexpected** … 149
Tight rope Ryuunosuke's Delusional Diary Part II … 153
Sugar Code Limited AGF book (2010) Special Illustration … 164
— Comic papers … 140, 165
— Illustrations and cuts … 172

Natsume Isaku Long Interview … 174
A look at my working space!! … 183
Super storyboard exhibit!! … 184
“Tightrope” OVA Creation plan exhibit!! … 185
Character rough plans exhibit!! … 186
Background illustrations exhibit!! … 188
“Heart's refuge” Tenement house room assignment and arrangement exhibit!! … 189
Natsume Isaku publication list … 190

Collection of stories
1-2. Story about chef with shaving fetish
3-5. PC and its software daily activities in human form.

From LuffyNoTomo:

In the modern day world, there is one who is born as the Maou (demon king) and one who is born as the Yuusha (hero). It's said that the hero is to defeat the demon king in both body and soul before the demon king tries to take over the world, but now a days who really believe in this stuff. Certainly not Mao who just so happens to be the reborn demon king. However, even though he has strange powers which makes other bad-guy type people fall for him, he has no intention of taking over the world.

One day the hero, Kamiko reaches Mao's office and notices right away that he is the demon king but in order to test this theory - he kisses him!
Mao just wants to get this defeat over with and go back to his daily life but when Kamiko seizes his company and says it's not going to be that easy. Mao's life is turned upside down and now they live together and Kamiko keeps insisting that the only way to be defeated properly is to have sex!