What order should I watch Nurarihyon no Mago in? What order should I watch "Nurarihton no Mago" and "Nurarihyon no Mago - Sennen Makyou" in? Because I'm pretty sure the events from episode 1 of the latter of the 2 take place before the events in the former of the 2. So is that the correct order I should watch them in?
In general, watching the anime in release order is the default recommendation, as also for this case:

Nurarihyon no Mago
Nurarihyon no Mago: Sennen Makyou

However, Japanese Wikipedia notes the differences in the anime adaptation from the original manga:

Session 1:

Episode 1 starts with the night-form of Rikuo confronting Gyuki on Mount Nejireme, then it continues to chapter 2 of the original manga.
[...]

Session 2:

Episode 1 broadcasts chapter 1 of the original manga.
[...]


So, chronologically (or &quot;more faithful manga order&quot;):

Season 2 Episode 1
Season 1 Episode 1-24
Season 2 Episode 2-24