Notes:

Woods of Illusion

As you can see, this figure is naked - see for myself, I'm not blind.
Apart from that you can see - nothing...
...no anatomical details, i.e. no gender characteristics.
The chest area is bare, as is the triangle in the crotch.
It is drawn like a doll - and since when have dolls been harmful to young people?

Furthermore, it is not a human being,
as the name of the ghost and her hair as a kind of second pair of arms suggest,
is she an elf or maybe some kind of plant that cannot be made out
because below neither feet nor roots can be seen.

Definitely a mythical creature.

ユグドラシルチェリィ   (Yugodora Cherries)?

No mythical creatures, the twins are human.
Also naked, but there is just as little to see.
However, these are only the basic images in the shell, which are not displayed by the ghost,
surface10000 and surface50000 are only basic elements of the surface0 and surface10 listed in surface.txt.
As with other complete advertisements, the individual representations are all combined with them and other images.
Is used in this way by many draftsmen in order to be able to dress the figures in different ways.
Is not given in this case, but possible.
The 'old shell' is in this style too.

The translation of the ghost name could also be "Yggdrasil's silver cherries", google can't really speak japanese...
Maybe mythical creatures after all?     (-_^)

LC-Familiar

Not the master shell, but one of the other two, namely 'Nails'.
Like the ones above, this figure is also naked - apart from that, you can't see anything...
...only the outline of the chest, but no further anatomical details.
Not quite drawn like a doll - but I still accept it.

You don't get to see the shell like this when the Ghost is running, Lila has a wardrobe.
Recomposed complete representations from individual images with surface0 as a basis.
The naked representation of surface0 makes it easier to adapt clothes,
whereby the draftsman determined, one could also say, restricted himself with regard to the chest size.
In the case of Lila and the twins as a whole, these figures are not intended for pedos,
especially since they, as like WoI, lack specific anatomical details.

The name of the character here, ライラクラム, google translates to 'Lyra Clam',
the installation file and directory are, however, 'Lilacram', hence the LC in the ghost name.
A translation error from google?   Only to a limited extent, the pronunciation of names is sometimes a mystery even to japanese people.
 
My assessment criteria:
 
1. Figures are naked, but chest area and triangle are bare or covered - harmless.
2. The triangle is like 1, but chest with nipples - rated 16, no direct links.
3. Even details in the triangle - !18! Links blocked, addresses in the page source text deleted.
4. !Hentai! - further representations, procedure as for 3.
5. Figures are clearly minors, naked with specific anatomical details, i.e. for pedos - procedure as for 3 and 4.
 
Additional measures:
Lettering on (most*) main pages of 3,4,5 deleted from the page source text and inserted into an alternative image file.
This prevents copy & paste for use as a search term in search engines!
*   'TCG*', '*2LDK' and 'Twinkle' can be entered without any problems, but then you get everything possible there, just not necessarily the pages...
Japanese people from a youthful age can certainly enter the lettering, but such pages and representations are allowed under japanese law!
Non-Japanese students with Japanese as a (second? or third?) foreign language also need a certain number of school years before they would be able to do so...
...and are then probably of legal age.