Need some help from someone who can more effectively express the nuance of what she's saying here. But this is the basic gist of it. She's saying Marisa is the strongest partner she's got, and they would be the strongest there is if they worked together.

Japanese twitter lost their shit over this and started shouting "ReiMari" all over it, but I have a sneaking suspicion that might be down to the fact that 二人 can also mean "couple".

Vid-szhite said:

Need some help from someone who can more effectively express the nuance of what she's saying here. But this is the basic gist of it. She's saying Marisa is the strongest partner she's got, and they would be the strongest there is if they worked together.

Japanese twitter lost their shit over this and started shouting "ReiMari" all over it, but I have a sneaking suspicion that might be down to the fact that 二人 can also mean "couple".

Probably the intended effect. Zun pushes the ReiMari button pretty hard in the manga.

Oh-ho, I just found the context that makes this line explode.

Reimu declared earlier in Yukari's arc that she and Yukari couldn't be beaten because they were the True Strongest Pair. She's implying here that she wishes it weren't true. She wants Marisa to practice working together with her, so that she can ditch Yukari, and she and Marisa would then become the Strongest Pair Ever.

This would even end up solving Dream Marisa's complaints about never getting to be the hero because of Reimu and Yukari. This is Reimu saying she wants her to succeed too, and she wants to help her get there, and be there when it happens. Indirectly, she's also saying she knows Marisa wouldn't need to become a Youkai to do it. She already has it in her, they would only need to practice.

That is why she blushes.

In a narrative sense, ZUN might also be setting the story up for her and Marisa to team up in the future, where they end up winning together, resolving the biggest incident yet as a team. Can you imagine? ReiMari fans would nut if that happened.

This was a case of ZUN tapping the YukaReimu button in the main story, and then pushing the ReiMari button even harder in the afterstory, just like he always does. Suddenly the reason Japanese twitter lost their shit makes all the sense in the world.