Look-alikes

Kana that look alike and get swapped all the time, grouped in pairs.

Why drill them separately?

In order they are easy, but shuffled at random the look-alikes start trading places.
Spot the difference side by side once, then drill just the pair shuffled — they separate quickly.
In listening practice the partner always shows up as a choice, so you pick by shape after hearing the sound.

ぬ (nu) · め (me) — ぬ ends in a small loop; め ends without one.
わ (wa) · れ (re) · ね (ne) — on the right, わ curls closed, れ kicks outward and ね ends in a loop.
る (ru) · ろ (ro) — る has a loop at the end; ろ stays open.
さ (sa) · ち (chi) — mirror images. ち opens to the left at the bottom, like the number 5.
は (ha) · ほ (ho) — ほ has one extra horizontal stroke at the top right.
い (i) · り (ri) — the right stroke of り runs much further down.

シ (shi) · ツ (tsu) — シ has its two dots stacked on the left, ツ has them side by side on top. The long stroke goes up in シ and down in ツ.
ソ (so) · ン (n) — ソ has its dot on top and the long stroke falls; ン has its dot on the left and the long stroke rises.
ク (ku) · ケ (ke) · タ (ta) — ケ has a horizontal stroke that runs far right; タ is ク with one more short stroke inside.
ス (su) · ヌ (nu) — ヌ has an extra short stroke crossing the middle.
コ (ko) · ユ (yu) — the bottom line of ユ sticks out to the right.
チ (chi) · テ (te) — the top stroke of チ slants down; in テ it is a flat line.

Pick a pair and its kana come up shuffled, always in the script shown on the chip.
They are the same kana as in the basic rows, so your records add up together.