Wuxings in Positive Action Background
Wuxings(五行) are the five &quot;elements&quot; in Chinese philosophy. They are Fire(火), Water(水), Wood(木), Metal(金), and Soil(土). You can find them on East Asian calendar, where some days (Tuesday through Saturday) are named by the Wuxings.
Some Korean names are given according to Wuxings, so that father's name will have a positive effect to his children. Let's simulate that.
Positive actions

Fire fertilizes Soil.
Soil incubates Metal.
Metal is a container for Water.
Water nourishes Wood.
Wood fuels Fire.

Negative actions
These are irrelevent to this challenge, but I'm showing them anyway.

Fire melts Metal.
Metal chops Wood.
Wood penetrates Soil.
Soil blocks Water.
Water extinguishes Fire.

Ideographs
Some ideographs have a Wuxing as its radical. Here, only the CJK Ideographs(U+4E00–U+9FFF), a Unicode block, will be considered as of Unicode 1.0.1.

火(U+706B)–爩(U+7229) have Fire as the radical.

水(U+6C34)–灪(U+706A) have Water as the radical.

木(U+6728)–欟(U+6B1F) have Wood as the radical.

金(U+91D1)–钄(U+9484) have Metal as the radical.

土(U+571F)–壪(U+58EA) have Soil as the radical.

All other characters fall in don't care situation.


Notes

Some characters, in Unicode's own dictionary, disagree with the categorization above. For example, 泵(U+6CF5) actually doesn't have Water as its radical, but rather &quot;石&quot;. For another example, 渠(U+6E20) has ambiguous radical, Water or Wood. Such characters also fall in don't care situation.

After Unicode 1.0.1, Unicode added more characters that has a Wuxing as their radical to the block and other blocks. For example, 龦(U+9FA6) also has Fire as its radical. This detail shall be ignored in this challenge, and such characters also fall in don't care situation.


Objective
Given an ideograph having a Wuxing \$W\$ as its radical, output any ideograph whose radical will be positively acted by \$W\$.
Examples
Given 溒(U+6E92), it has Water as its radical, so output any ideograph having Wood  as its radical, since Water nourishes Wood. For example, 杜(U+675C).
Given 坽(U+577D), it has Soil as its radical, so output any ideograph having Metal as its radical, since Soil incubates Metal. For example, 鉺(U+927A).
JavaScript (Node.js), 39 bytes
I/O: Unicode codepoints as integers.
n=&gt;Buffer(&quot;99944,777I&quot;)[n/543%62&amp;15]&lt;&lt;9

Try it online!
How?
Step 1
We first look for some divisor \$d\$ such that the following element sets \$S_k\$ are disjoint:
$$S_k=\left\{\left\lfloor\dfrac{n}{d}\right\rfloor,\:C_{min}(k)\le n\le C_{max}(k)\right\}$$
where \$C_{min}(k)\$ and \$C_{max}(k)\$ are the codepoint bounds of the \$k\$-th element.
Because the Unicode range of Water (U+6C34 to U+706A) is immediately followed by the Unicode range of Fire (U+706B to U+7229), there are not many possible options for \$d\$: it must be a proper divisor of \$28779\$ (0x706B), i.e. \$d\in\{1, 3, 53, 159, 181, 543, 9593\}\$. The best value in there that actually works is \$d=543\$.
Step 2
We then look for some modulo chain that takes \$n\$ as input and turns it into an index corresponding to the counterpart element, using \$n/543\$. Instead of rounding the result towards zero, we force the last operation to a bitwise AND rather than a modulo.
A quick brute-force search leads to:
$$f(n)=((n/543)\bmod 62)\operatorname{and}15$$
Step 3
Finally, we look for some multiplier \$m\$ such that there exists some \$q_k\$ for each \$k\$ that satisfies:
$$C_{min}(k)\le q_k\times m\le C_{max}(k)$$
One possible golf-friendly value is \$m=512\$, leading to the following table:
 element | hexa range      | q  | q*512 | as hexa
---------+-----------------+----+-------+---------
  Soil   | 0x571F - 0x58EA | 44 | 22528 | 0x5800
  Wood   | 0x6728 - 0x6B1F | 52 | 26624 | 0x6800
  Water  | 0x6C34 - 0x706A | 55 | 28160 | 0x6E00
  Fire   | 0x706B - 0x7229 | 57 | 29184 | 0x7200
  Metal  | 0x91D1 - 0x9484 | 73 | 37376 | 0x9200

The values of \$q\$ are encoded as the ASCII codes of ,479I.