<s>
is	O
a	O
late	O
night	O
anime	O
TV	O
series	O
created	O
by	O
Ayana	O
Itsuki	O
that	O
is	O
adapted	O
from	O
a	O
PC-9801	B-Operating_System
game	O
of	O
the	O
same	O
name	O
.	O
</s>
<s>
Nightwalker	O
incorporates	O
elements	O
of	O
the	O
horror	O
,	O
detective	O
story	O
and	O
vampire	B-Application
genres	O
,	O
and	O
is	O
critically	O
noted	O
as	O
a	O
vampire	B-Application
story	O
"	O
with	O
a	O
bit	O
of	O
a	O
twist	O
"	O
.	O
</s>
<s>
The	O
main	O
character	O
is	O
Shido	O
,	O
a	O
vampire	B-Application
who	O
protects	O
humans	O
from	O
other	O
supernatural	O
creatures	O
.	O
</s>
<s>
is	O
a	O
16-color	O
PC-9801	B-Operating_System
eroge	B-Application
released	O
by	O
Tomboy	O
in	O
December	O
1993	O
.	O
</s>
<s>
In	O
2001	O
the	O
developer	O
Arieroof	O
remade	O
this	O
game	O
for	O
Windows	B-Application
2000	I-Application
as	O
just	O
Nightwalker	O
.	O
</s>
<s>
Shido	O
,	O
the	O
main	O
character	O
of	O
the	O
series	O
,	O
is	O
a	O
vampire	B-Application
who	O
decided	O
to	O
defend	O
humans	O
against	O
his	O
demonic	O
brethren	O
as	O
atonement	O
for	O
the	O
sins	O
he	O
committed	O
early	O
in	O
his	O
vampiric	O
life	O
.	O
</s>
<s>
He	O
knows	O
little	O
of	O
his	O
life	O
prior	O
to	O
becoming	O
a	O
vampire	B-Application
,	O
and	O
even	O
his	O
name	O
is	O
a	O
pseudonym	O
he	O
took	O
when	O
he	O
arrived	O
in	O
Japan	O
.	O
</s>
<s>
He	O
is	O
also	O
a	O
vampire	B-Application
with	O
the	O
ability	O
to	O
manipulate	O
his	O
own	O
blood	O
to	O
form	O
weapons	O
.	O
</s>
<s>
He	O
is	O
a	O
quarter-vampire	O
(	O
one	O
of	O
his	O
grandfathers	O
was	O
a	O
full-blood	O
vampire	B-Application
,	O
and	O
the	O
rest	O
of	O
his	O
family	O
line	O
is	O
of	O
Japanese	O
descent	O
)	O
,	O
Shidō	O
has	O
inherited	O
guardianship	O
of	O
the	O
passage	O
between	O
the	O
mortal	O
world	O
and	O
the	O
demon	O
world	O
,	O
but	O
otherwise	O
he	O
lives	O
as	O
a	O
human	O
.	O
</s>
<s>
Riho	O
idolizes	O
Shido	O
and	O
works	O
as	O
his	O
secretary	O
,	O
but	O
is	O
initially	O
unaware	O
of	O
that	O
he	O
is	O
a	O
vampire	B-Application
.	O
</s>
<s>
Shidō	O
drinks	O
Riho	O
's	O
blood	O
in	O
the	O
finalé	O
of	O
the	O
game	O
,	O
and	O
she	O
becomes	O
a	O
vampire	B-Application
.	O
</s>
<s>
Cain	O
transformed	O
Shido	O
into	O
a	O
vampire	B-Application
long	O
before	O
the	O
main	O
events	O
of	O
the	O
series	O
.	O
</s>
<s>
The	O
soundtrack	O
for	O
the	O
Nightwalker	O
anime	O
,	O
composed	O
by	O
Akifumi	O
Tada	O
,	O
is	O
noted	O
for	O
its	O
jazz	B-Device
themes	O
and	O
prominent	O
use	O
of	O
saxophones	O
.	O
</s>
<s>
In	O
Japan	O
,	O
Nightwalker	B-Application
:	I-Application
The	I-Application
Midnight	I-Application
Detective	I-Application
aired	O
on	O
TV	O
Tokyo	O
and	O
was	O
later	O
released	O
on	O
VHS	O
in	O
1998	O
on	O
six	O
VHS	O
tapes	O
with	O
two	O
episodes	O
each	O
.	O
</s>
